Gli autori ringraziano il Midwestern University ufficio di ricerca e programmi sponsorizzati per il loro sostegno.

1. preparare supporti per coltura anaerobica di varie linee cellulari di mammifero
<ol><li>
Rendere il completo supporto di PS-74656 per un cellulare anossica cultura25.
	<ol>
<li>Rendere la soluzione madre di nitrito sterile (5m; 100 x) sciogliendo 17,25 g di nitrito in 50 mL di acqua distillata o deionizzata, quindi filtrare per sterilizzarlo.</li>
		<li>Aggiungere 0,5 mL della soluzione madre nitrito per 50 mL di glucosio basso DMEM (1 g/L di glucosio) con 110 mg/L di L-Glutammina, 584 mg/L di sodio piruvato e 10% siero bovino fetale (FBS; inattivati al calore). Nota: L'uso di FBS concentrazioni superiore a 10% sono tossici. Della nota, una linea cellulare di cancro testata aveva una bassa tolleranza per i media con il nitrito (MDA-MB-231, linea di cellule di cancro al seno) e, quindi, è stata coltivata in assenza di nitrito. Inoltre, anche se PS-74656 medio sostenuto la crescita di tutte le linee cellulari che sono stati testati (n = 9), alcune linee cellulari (ad es., cellule Vero) hanno esibito le più alte concentrazioni di cellule e una redditività superiore in PS-74656 con alto glucosio (4,5 g/L) DMEM 25.</li>
		<li>Posto 20 mL di terreno in una provetta conica sterile 50 mL. Non serrare il tappo; esso dovrebbe essere sciolto.</li>
		<li>De-gas medio inserendo il tubo in una campana di vetro vuoto a un angolo di circa 45 °, per massimizzare l'area di superficie media.</li>
		<li>Applicare un vuoto utilizzando una pompa a vuoto, o il suo equivalente, a temperatura ambiente. Mantenere il vuoto fino a quando le bolle non sono non più osservate (24-48 h).</li>
		<li>Rimuovere il tubo dalla vaschetta e chiudere immediatamente il tappo, il tubo per ridurre al minimo l'introduzione di aria nel mezzo di tenuta.</li>
		<li>Inserire il tubo nella camera anaerobica commerciale.</li>
		<li>Svitare il tappo del tubo e consentire l'atmosfera nel tubo da equilibrare con quello della miscela gas anaerobico nella camera per almeno 24 h. Nota: Il mezzo dovrebbe rimanere nella camera fino ad esaurimento. Per accelerare il processo, a filo il tubo almeno 3 volte con la miscela di gas anossico utilizzando una pipetta sterile riempita di gas anossico, che consiste di N, CO2e H22.
</li>
		<li>Degassare tutte le provette (10 – 15 min) collocate nella camera anaerobica come descritto in precedenza prima di sigillare il tubo e immissione nella camera. Prima dell'uso, lavare con la miscela di gas anaerobica utilizzando pipette di trasferimento di 1,5 – 2 mL o puntali che sono state svuotate con anossico gas almeno 3 volte.</li>
		<li>Mentre nella camera anaerobica, rimuovere 100 µ l del mezzo in una provetta sterile da micro-centrifuga degassato e testarlo per l'ossigeno disciolto utilizzando una sonda di ossigeno all'interno della camera. Nota: L'elettrodo di ossigeno è calibrato per prima del protocollo del produttore utilizzare. Letture dei media miscela gas anaerobico correttamente degassato ed equilibrato sono 0. Attenzione: Se le letture sono superiori a 0,3 ppm di ossigeno, continua a incubare i media nella camera anaerobica poiché è necessario più tempo per equilibrare il medium.</li>
	</ol>
</li>
</ol>2. anossico coltivazione di varie linee cellulari di mammifero
<ol><li>
Area giorno -1
	<ol>
<li>Crescere le cellule (37 ° C, 5% CO2) in un matraccio da T150 alla confluenza del 90% per il controllo di cultura anossico e normoxic fornire un numero sufficiente di cellule per tre piastre da 24 pozzetti (80% confluenza). Nota: Per questo studio, le cellule HeLa 229 e Vero sono state usate. Questo protocollo è stato anche testato e ha dimostrato riuscito per la crescita e la manutenzione di sette altre linee cellulari25.</li>
		<li>Rimuovere il supporto dal pallone di aspirazione e lavarlo con 10 mL di HBSS.</li>
		<li>Sostituire il mezzo con 5 mL di tripsina. Agitare il pallone fino a quando le cellule visivamente staccano dalla plastica. Aspirare la maggior parte della tripsina, quindi tocca il pallone per sloggiare le celle aderenti. Aggiungere 10 – 15 mL di alto glucosio DMEM (4,5 g/L di glucosio, 110 mg/L di L-Glutammina, 10% FBS, 50 µ g/mL di gentamicina) per inattivare la tripsina.</li>
		<li>Triturare le celle utilizzando una pipetta da 25 mL, fino a quando tutti i grumi di cellule sono interrotti.</li>
		<li>Contare le celle e determinare la fattibilità utilizzando l'emocitometro standard e il metodo di esclusione del colorante blu di trypan o l'equivalente automatizzato.</li>
		<li>Sospendere le cellule nell'alto glucosio DMEM come accennato in precedenza ad una densità di cella di 2,24 x 105 cellule/mL.</li>
		<li>Aggiungere 1 mL di sospensione cellulare dei pozzetti di una piastra di coltura del tessuto 24 pozzetti (2,24 x 105 cellule/pozzetto; 80% confluenza). 1 piastra per la cultura anossica e un altro per una cultura di normoxic controllo del seme.</li>
		<li>Incubare le cellule a 37 ° C in condizioni di normossia (5% CO2) per 24 h. Nota: Le celle possono essere placcate in varie piastre ben dimensionati. Tuttavia, semina le cellule per una crescita anossica in boccette corre il rischio dell'introduzione di ossigeno nel sistema, a meno che la cura è esercitata per scovare completamente gas atmosferici.</li>
	</ol>
</li>
	<li>
Giorno designato 0
	<ol>
<li>Dopo 24 h di incubazione normoxic, posizionare le piastre per la crescita anossica nella camera anaerobica (un alloggiamento anaerobico commerciale; Figura 1).</li>
		<li>Cambiare immediatamente il mezzo privo di antibiotico de-gasati PS-74656 medio che ha stati acclimatati per 24 h alla camera anaerobica. Posizionare la piastra in un contenitore con un panno umido e chiuderlo senza bloccare per mantenere l'umidità. Nota: Le piastre per la crescita in condizioni di normossia sono gestite in modo identico con l'eccezione che tutti i trattamenti avvengono in condizioni atmosferiche.</li>
	</ol>
</li>
	<li>
1 ° giorno designato
	<ol>
<li>1 ° giorno di incubazione anaerobica inizia dopo 24 h di incubazione nella camera anaerobica commerciale che contiene la miscela di gas anaerobico standard di 10% H2, 10% CO2e 80% N2.</li>
		<li>Incubare le cellule per vari periodi di tempo.</li>
		<li>Monitorare il mezzo anaerobico per il cambiamento di colore nel tempo. Nota: Un cambiamento di colore da rosso-arancio al magenta segnala il momento di cambiare il mezzo. Questo può richiedere fino a 2 settimane per verificarsi. Un cambiamento di colore nel mezzo da rosso-arancio al giallo indica la presenza di una contaminazione batterica.</li>
		<li>Quando il mezzo cambia da rosso a magenta, rimuovere le cellule di runagate dall'aspirazione.</li>
		<li>Posizionare il supporto di speso aspirato con le cellule di runagate a gas degassato e anaerobica equilibrato microfuge tubi, chiudere i tubi mentre assicurandosi che la guarnizione è sicura e poi centrifugare li (326 x g; a temperatura ambiente per 10 min). Sostituire immediatamente i media aspirati nel pozzo con 1 mL di nuovo mezzo di PS-74656 degassato.</li>
		<li>Posizionare il tubo di microfuge con pellettate cellule nella camera anaerobica prima di aprirlo. Aspirare il mezzo esaurito e sostituirlo con mezzo PS-74656 degassato fresco per un volume totale di 1 ml nel tubo del microfuge.</li>
		<li>Restituire le cellule dal tubo ad un pozzo nella piastra di coltura del tessuto 24 pozzetti.</li>
	</ol>
</li>
</ol>3. valutazione di differenziazione fenotipica delle cellule mediante microscopia di cellule coltivate in condizioni aerobiche
<ol><li>
Mentre nella camera anaerobica, posizionare la piastra in una scatola richiudibile lavata con la miscela di gas anaerobico e chiudere la finestra. Nota: La casella deve contenere un tovagliolo di carta umido per fornire umidità e prevenire la piastra dall'asciugarsi. Per microscopia, sacchetti per sandwich funzionano al meglio, dal momento che sono sottili.<ol>
<li>Per osservare le cellule al microscopio, completamente sigillare il sacchetto e rimuoverlo dalla camera.</li>
		<li>Con attenzione allungare il sacchetto di plastica sopra la piastra, esaminare cellule utilizzando un microscopio di contrasto di fase invertito con l'allegato di fotocamera e prendere microfotografie a vari ingrandimenti.</li>
		<li>Restituire la lastra nel sacchetto sigillato alla camera e continuare l'incubazione come descritto al punto 2.3.3.</li>
		<li>Per analizzare separatamente le cellule runagate che sono in sospensione, attenersi alla procedura descritta al punto 2.3.5. Nota: Queste cellule possono quindi essere utilizzate per il test aerobico o possono essere restituite alla camera anaerobica per la sperimentazione di questa specifica popolazione.</li>
	</ol>
</li>
</ol>

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Questo metodo rappresenta la prima volta le cellule di mammiferi che sono state coltivate per lunghi periodi di tempo in assenza di ossigeno. Sulla base di osservazioni attuale la crescita anossico capacità tramite una via non-fermentativo sembra essere universale tra le cellule di mammiferi linee28, dove la crescita anaerobica ha provocato la divergenza di fenotipo. Questo è stato osservato per tutte le linee cellulari testate. Con la coltura anaerobica, aumentando le proporzioni delle...

Le cellule dai tumori solidi, nicchie di cellule staminali e quelle rivestimento superfici mucose presenti in ambienti che sperimentano livelli di ossigeno ridotto, tra cui anossia1,2,3,4. In condizioni fisiologiche normali, ossigenazione varia oltre quello di ipossia per anossia (la completa assenza di ossigeno)5,6. La realizzazione che ossigeno atmosferico influisce negativamente sulla replica delle cellule dei mammiferi e tale crescita in vitro delle cellule può essere ottimizzata in condizioni impoverito di ossigeno è stata segnalata nei primi anni 1970. Richter et al. 7 ha mostrato che 1 – 3% dei livelli di ossigeno (ipossia) migliorare l'efficienza della placcatura rispetto ad ossigeno atmosferico (20%). La durata della vita umana cellula diploide è esteso anche in condizioni ipossiche cultura8.
In vivo, condizioni di ipossia si verificano quando i negozi di ossigeno sono impoverito (ad es., durante l'esercizio intenso), in cui la produzione di ATP è inserita nel muscolo scheletrico da respirazione aerobica alla fermentazione (respirazione anaerobica) con la prodotto finale di acido lattico9. Patologico, in tumori cancerosi, all'interno del tumore massa è ipossica a anossico a causa della scarsa vascolarizzazione10. L'effetto della perfusione limitata all'interno del tumore viene convalidato indipendentemente da interni di tumore colonizzati da anaerobi1. Meccanicistico, sopravvivenza delle cellule del tumore nell'ipossia è pensata per essere dipendente unicamente sull'espressione del gene di 1 alfa fattore ipossia-inducibile (HIF1-alfa), che è la prima risposta spontanea alla ipossia4,11 , 12. HIF1-alfa è indotta in condizioni di ipossia da proteine dello shock termico che legano il HIF1-alfa promotore e aumentano la trascrizione genica12. Si ritiene che queste proteine di scossa di calore aiuto nell'induzione dei vari fenotipi visto nel microambiente tumorale ipossica. Questi fenotipi mostrano un incremento dell'espressione dei trasportatori del glucosio della membrana cellulare e il tasso di glicolisi (l'effetto Warburg)13. Il risultato è un interruttore da fosforilazione ossidativa mitocondriale di lattato fermentazione.
Anossico sopravvivenza possa anche utilizzare delle alternative a glucosio per sostenere la sopravvivenza fenomeno14,15. Il miglior esempio di mammiferi studiato è il Ratto talpa, che possono sopravvivere per quasi 20 minuti senza ossigeno attraverso una fermentazione glicolitico fruttosio-driven via14. Un adattamento alternativo si verifica in alcuni pesci (ad es., carpa [Carassius SP.], che possa sopravvivere per significativamente più lungamente periodi utilizzando glicolisi con etanolo come il sottoprodotto terminale di tempo)15. In entrambi i casi, fermentazione unità il metabolismo consentendo la sopravvivenza in assenza di ossigeno. L'ipotesi corrente per la sopravvivenza anossico è che così a lungo come HIF1-alfa è attivato durante l'ipossia, la respirazione mitocondriale, senza la necessità di ossigeno, si verifica in condizioni anaerobiche16. Inoltre, è postulato che l'uso di una via fermentativa per sopravvivenza ipossico/anossico migliora la sopravvivenza del tumore dal momento che le cellule evitare stress ossidativo che potrebbe rivelarsi dannosa per la sopravvivenza delle cellule17. Questo postulato è supportato da uno studio recente che mostra che in cardiomiociti, ipossia riduce lo stress ossidativo collocato sul tumore cella17.
Fin qui, la natura essenziale di una via fermentativa per la sopravvivenza della cellula di mammiferi anossico è stata radicata nella letteratura, dovute, in gran parte, ad un'incapacità di cellule di mammifero di cultura in completa assenza di ossigeno per più di 3 giorni. Tuttavia, un'alternativa alla glicolisi per la sopravvivenza anaerobica si verifica nei batteri. In alcuni batteri, azoto o solfato (tra altri composti) può servire come accettori terminali per il sistema del citocromo ossidasi in assenza di ossigeno18. Sebbene l'evoluzione batterica ed eucariotica è avvenuta in parallelo dal divergenti dall'ultimo antenato comune universale, si stima che i mitocondri sono state fornendo energia alle cellule per 1,542 milioni anni prima l'ossigenazione degli oceani19 . Poiché i ricercatori hanno indicato che i mitocondri isolati possono produrre ATP in assenza di ossigeno, con nitrito come accettore terminale di elettroni, è ragionevole supporre che le cellule potrebbero funzionare per periodi di tempo più lungo di 3 giorni in assenza di ossigeno 20 , 21 , 22 , 23. la metodologia descritta in questo studio è un programma di utilità per la crescita di cellule di mammifero anaerobica di numerose linee cellulari.

<table border="0" cellpadding="0" cellspacing="0" style="width:709px;" width="709">
	<tbody>
		<tr height="147">
			<td height="147" style="height:147px;width:255px;">Whitney A35 anaerobic chamber</td>
			<td style="width:149px;">Don Whitley Scientific&#160;</td>
			<td style="width:139px;">Microbiology International</td>
			<td style="width:167px;">The ability to remove the front of the chamber makes it easy to put instruments inside without concern about getting them through the portals.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">CO2 incubator</td>
			<td style="width:149px;">Fisher Scientific</td>
			<td style="width:139px;">3531</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Tissue Culture Hood</td>
			<td style="width:149px;">Labconco</td>
			<td style="width:139px;">DO55735</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:255px;">pipet aid</td>
			<td style="width:149px;">Drummond</td>
			<td style="width:139px;">4-000-100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">sterile transfer pipets</td>
			<td style="width:149px;">Santa Cruz</td>
			<td style="width:139px;">sc-358867</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">50cc sterile conical centrifuge tubes</td>
			<td style="width:149px;">DOT</td>
			<td style="width:139px;">451-PG</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:255px;">vaccum jar</td>
			<td style="width:149px;">Nalgene 111410862889</td>
			<td style="width:139px;">BTA-Mall 5311-0250</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">DMEM high glucose (4.5 g/L)</td>
			<td style="width:149px;">CellGro</td>
			<td style="width:139px;">10-017-CM</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">DMEM low glucose (1 g/L)</td>
			<td style="width:149px;">CellGro</td>
			<td style="width:139px;">10-014-CV</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">FBS</td>
			<td style="width:149px;">VWR</td>
			<td style="width:139px;">1500-500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">HBSS</td>
			<td style="width:149px;">VWR</td>
			<td style="width:139px;">20-021-CV</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">trypsin</td>
			<td style="width:149px;">VWR</td>
			<td style="width:139px;">25-052-CI</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">gentamicin</td>
			<td style="width:149px;">Gibco</td>
			<td style="width:139px;">15750-060</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">sterile pipets</td>
			<td style="width:149px;">CellTreat</td>
			<td style="width:139px;">229210B, 229205B</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Tissue culture flask (T75 or T150)</td>
			<td style="width:149px;">Santa Cruz</td>
			<td>sc-200263, sc-200264</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">24 well tissue culture treated dishes</td>
			<td style="width:149px;">DOT</td>
			<td style="width:139px;">667124</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">glad ziplock sandwich bags</td>
			<td style="width:149px;">Ziploc</td>
			<td style="width:139px;">Costco</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:255px;">inverted phase microscope (10, 20 40x objectives with camera mont)</td>
			<td style="width:149px;">Nikon Eclipse</td>
			<td style="width:139px;">TS100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">trypan blue</td>
			<td style="width:149px;">Invitrogen</td>
			<td style="width:139px;">T10282</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">hemocytometer</td>
			<td style="width:149px;">Invitrogen</td>
			<td style="width:139px;">C10283</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Countess Automated Cell Counter</td>
			<td style="width:149px;">Life Technologies</td>
			<td style="width:139px;">AMQAF1000</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:255px;">Rainin microtiter pipets</td>
			<td style="width:149px;">Mettler Toledo</td>
			<td style="width:139px;">Rainin Classic Pipette PR-100</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:255px;">microtiter tips</td>
			<td style="width:149px;">Santa Cruz Biotechnology</td>
			<td style="width:139px;">sc-213233 &#38; sc-201717&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">test tube rack (50cc tubes)</td>
			<td style="width:149px;">The Lab Depot</td>
			<td>HS29050A</td>
			<td></td>
		</tr>
		<tr height="105">
			<td height="105" style="height:105px;width:255px;">sodium nitrite</td>
			<td style="width:149px;">Sigma</td>
			<td style="width:139px;">https://www.sigmaaldrich.com/catalog/product/sigald/237213?lang=en&#38;region=US</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">clear boxes with lids</td>
			<td style="width:149px;">Rosti Mepal</td>
			<td style="width:139px;">Rubber maid</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">paper towels</td>
			<td style="width:149px;">In House</td>
			<td style="width:139px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">cell scraper</td>
			<td style="width:149px;">CellTreat</td>
			<td style="width:139px;">229310</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">PBS</td>
			<td style="width:149px;">In house prepared</td>
			<td style="width:139px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">70% Ethanol</td>
			<td style="width:149px;">Fisher Scientific</td>
			<td style="width:139px;">64-17-5</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">microcentrifuge tubes sterile</td>
			<td style="width:149px;">Santa Cruz</td>
			<td style="width:139px;">sc-200273</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">biohazard bags with holder (desktop)</td>
			<td style="width:149px;">Heathrow Scientific</td>
			<td style="width:139px;">HS10320</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Nitrile Gloves</td>
			<td style="width:149px;">VWR</td>
			<td style="width:139px;">89428</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">oxygen electrode</td>
			<td style="width:149px;">eDAQ</td>
			<td style="width:139px;">EPO354</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">pH meter</td>
			<td style="width:149px;">Jenway</td>
			<td style="width:139px;">3510</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">pH paper/ pHydrion</td>
			<td style="width:149px;">Sigma Aldich</td>
			<td>Z111813</td>
			<td></td>
		</tr>
	</tbody>
</table>

anaerobic growth and maintenance of mammalian cell lines

Più superfici mucose insieme i punti medi in tumori e nicchie staminali sono aree geografiche del corpo che sono anossiche. Gli studi precedenti indicano che l'incubazione in condizioni di normossia (5% CO2 nell'aria) o hypoxic condizioni (bassi livelli di ossigeno) seguirono da un risultati di incubazione anossico (un'assenza di ossigeno libero) nell'attuabilità limitato (2 – 3 giorni). Una nuova metodologia è stata sviluppata che consente una coltura cellulare anossica (per almeno 17 giorni; il tempo massimo testato). L'aspetto più critico di questa metodologia è quello di garantire che nessun ossigeno è stato introdotto nel sistema. Ciò si ottiene il degassamento dei media e di lavaggio tubi, piatti, boccette e le pipette con una miscela di gas anaerobico (H2, CO2, N2) seguita da permettendo i materiali per equilibrare l'ambiente anossico (non-ossigeno) prima dell'uso. Maggiore cura deve essere esercitato quando l'acquisizione di microfotografie per garantire che le micrografie ottenute non contengono artefatti. In assenza di ossigeno, la morfologia delle cellule è alterata significativamente. Due morfotipi distinti sono noti per tutte le cellule coltivate in condizioni aerobiche. La capacità di crescere e mantenere le cellule di mammiferi in assenza di ossigeno può essere applicata all'analisi della fisiologia cellulare, interazioni polimicrobica e la caratterizzazione delle vie biosintetiche per lo sviluppo di farmaci innovarici del cancro.

La forza di questo protocollo sta nel suo sostegno la longevità e la crescita di linee cellulari multiple e nel riconoscimento che ci sono una profonda alterazione e la divergenza nella morfologia delle cellule25. L'elemento più critico di questo studio è il trasferimento e la manutenzione delle cellule sotto rigorosa anaerobiosi. Ciò richiede una camera anaerobica organizzato per massimizzare il protocollo (Figura 1) e l'assicuraz...

Watch this Scientific Journal Video about Anaerobic Growth and Maintenance of Mammalian Cell Lines at JoVE.com

Anaerobic Growth and Maintenance of Mammalian Cell Lines

Crescita anaerobica e la manutenzione di linee cellulari di mammifero

Qui, descriviamo un nuovo metodo che consente la coltivazione anaerobica a lungo termine di linee cellulari stabilizzate. Il tempo di sopravvivenza massima che è stato testato è di 17 giorni. Questo metodo è adatto per la sperimentazione di agenti citotossici ed esplorare la fisiologia di replicare anoxically cellule.

Most mucosal surfaces along with the midpoints in tumors and stem cell niches are geographic areas of the body that are anoxic. Previous studies show that ...

anaerobic-growth-and-maintenance-of-mammalian-cell-lines

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Biology

10.0K Views.  Midwestern University. Qui, descriviamo un nuovo metodo che consente la coltivazione anaerobica a lungo termine di linee cellulari stabilizzate. Il tempo di sopravvivenza massima che è stato testato è di 17 giorni. Questo metodo è adatto per la sperimentazione di agenti citotossici ed esplorare la fisiologia di replicare anoxically cellule.

Video: Anaerobic Growth and Maintenance of Mammalian Cell Lines

Passaging HuES Human Embryonic Stem Cell-lines with Trypsin.

In this video we demonstrate how our lab routinely passages HuES human embryonic stem cell lines with trypsin.  Human embryonic stem cells are artifacts of cell culture, and tend to acquire karyotypic abnormalities with high population doublings.  Proper passaging is essential for maintaining a healthy, undifferentiated, karyotypically normal HuES human embryonic stem cell culture.  First, an expanding culture is washed in PBS to remove residual media and cell debris, then cells are overlaid with a minimal volume of warm 0.05% Trypsin-EDTA.  Trypsin is left on the cells for up to five minutes, then cells are gently dislodged with a 2mL serological pipette.  The cell suspension is collected and mixed with a large volume of HuES media, then cells are collected by gentle centrifugation.  The inactivated trypsin media mixture is removed, and cells resuspended in pre-warmed HuES media.  An appropriate split ratio is calculated (generally 1:10 to 1:20), and cells re-plated onto a 1-2 day old plate containing a monolayer of irradiated mouse embryonic fibroblast feeder cells.  The newly seeded HuES culture plate is left undisturbed for 48 hrs, then media is changed every day thereafter.  It is important not to trpsinize down to a single cell suspension, as this increases the risk of introducing karyotypic abnormalities.

In this video we demonstrate how our lab routinely passages HuES human embryonic stem cell lines with trypsin. Brought to you by JoVE.

RIFLESSI Passaging sulle cellule staminali embrionali umane-linee con tripsina

In this video we demonstrate how our lab routinely passages HuES human embryonic stem cell lines with trypsin.  Human embryonic stem cells are artifacts ...

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Biologia

Long-term Imaging Mammalian Cells using Wide-Field Microscopy

Actually what I'm gonna do, mount it in here first and then swap out You. So now I'm gonna aspirate try and be as gentle as possible.Okay. A few seconds just holding.Okay.Alright.So the important features of our lifestyle imaging grid are that, so it's an inverted scope, which means the objective, the samples here in the objective is underneath. So the objective is pointing up and the whole scope, or practically the whole, practically the whole scope, including the objectives and the sample are at 37 degrees. So everything in this plastic box is at 37 degrees.And right on top of the stage we have an air and CO2 mix. That is 5%CO2. So the idea is that the sample is actually in a cell, it's like a cell incubator.And so we have, this is our mixer for the air and the CO2 and, and it gets humidified and heated and then piped onto the, the sample on the stage.Okay. And today we're just gonna be doing fluorescence one channel GFP fluorescence. This is the hose that the CO2 and 5%CO2 goes in and it just fits into the stage holder.That's important. And then we can close these, take these down, and then we go to our first position. And what I'm gonna do is go to the first field, which is my control sample, and I'll pick positions based on what I see on the screen.So I just make sure I actually look into the microscope in each new, well, because the focal plane for each of the wells is different, the, the dish is not perfectly flat on the bottom. So you will need to make fine adjustments when you move from well to the well. So right now I'm on the first, well, what I'll do is I'll focus, so I just hit, I just told, I just turned on the light, the transmitted light for the microscope.And I have make sure all the light is going to the eye pieces. And so I just look in, make sure I get a nice clean field. And then what I'll do is turn that light off, turn the fluorescence light on, make sure the cells that I'm looking at look healthy and they're not apoptotic.And, and I turn that off. And what I do next is send, so now I'm gonna start picking positions, which means I have to te send the light path to the camera. This is the camera right here.So I tell the microscope to send all the camera, they don't see anything in the eye pieces. What I'll do is in the software controlling the microscope, I'll choose the right filter set, which for our purposes is psy. And then set an exposure time.And I know these cells very well and I know that they take a 0.2 second exposure time. So I tell, that's what I tell the software to do. And what I'll do is hit focus.This is, and it's basically just alive. The, A light will turn on and you can, oh, I don't know if you can see cells, but the reason this is a good field is because there's, all the cells are, even in terms of their fluorescence, There are no apoptotic cells. Apoptotic cells tend to be very bright and there's no dirt or schmutz in the field.And you can see that they're actually, this is a metaphase cell and that's a metaphase cell, that's a cell that's probably just exited mitosis. And I can just tell that because it looks like those are, those two sets of chromatin are very nicely oriented to each other. Like they just exited an face.So that's a good field. So, and now that I know that the exposure time and the filter set is correct, and this is gonna be software specific, I'll go and I'll take positions and now the software has memorized the X, Y, Z position of that field. And then when I do pick another field, it's, and I'll, so when I'm picking, when I'm picking new fields, but in the same, well, I'll use the, I'll move the i'll, I'll turn the shutter, I'll open the shutter and I'll look to see what I see on the screen and I'll pick fields based on that versus looking in the field.So I don't see any of my tonics in there. But again, even nicely centered, these cells will go through my PS I continue, here's a good example. Here's a good example of what I would avoid that, see how bright that is?That's very bright. That's probably remnants of an apoptotic cell. And the reason I would avoid that is because since it's so bright, when the software auto focuses, it will autofocus just on that and it won't be in the same plane as all these other cells.And so I won't get any information from that field. That looks nice. There's a, this is a pro metaphase right here, That's A metaphase.So, and I'm gonna take three positions per well. So that was three positions and now I'm going to go to my next Well, so you can, so what I will probably do is take images every 10 minutes. So it's a compromise.Lifestyle imaging is always a compromise, right? You have to image, you have to keep the cells healthy, especially if you're interested in mitosis. So you have to minimize their exposure to the fluorescent line.And, but you wanna get information. So you have to take images, you have to, so you have to compromise, you have to make a choice about what you want to capture, what kind of information you wanna capture. For our purposes, mitosis tends to take about an hour.So if we're taking 10 minute intervals, that's pretty good. We see prophase, we see metaphase, we see anaphase, and we can, we can see when there are, there are treatments or drugs or siRNAs that affect those specific cell cycle stages. So for our purposes, that's enough, but we always want more.We always want more positions or finer time and interval or something like that. So it's a compromise. So, and then I'll hit start.And so our software, it does an autofocusing pass on the first pass. So once I hit start, it should start auto autofocusing and you'll see the shutter open, open and close between auto focusing. So I'll hit start.So that's the shutter opening and closing. The Z motor is engaging and it's actually trying to find the plane with the most contrast, which will be the most in focus. You can actually see on the screen going in and out of finding the best plane of focus that might be worrisome.So what it does is it, it drives the Z motor to find the best, the most in focus plane focus, well the most in image. And then it acquires picture there and then it learns that Z position. And then we'll use that Z position for the next 12 passes.And then we'll do the auto focusing pass again. What Kind of experiments do they do? Okay, so our lab is mostly interested in understanding what regulates mitic progression, or at least I'm most interested in understanding that.So with live cell imaging and especially our multi position, long-term imaging scope, you can take, you can film cells for two or three days entering anding mitosis, and you can image multiple rounds of mitosis so you can understand. And then you can put drugs or RNAs or any kind of perturbations on the cells that you would like to study. So you can understand how, how those drugs or, or genes are, are important in regulating mitotic progression.Because it's not fixed cell work and live cell work, you can understand what, when you need to have a perturbation to affect mitosis or what stage of mitosis is affected. So it's really powerful in that respect. What, what are the main technical elements of this experiments?What are the possible problems? Well, the biggest problem besides getting the rig set up, getting the rig set up is not trivial. A lot of people have the rig, but just making sure it works well for your application.The financial element is not, you know, is not small. So there's the setting up of the apparatus and then, and then once you gather the data, there's a real data analysis issue. It takes these movie, if, so, if you're gathering 40 movies each with 30 cells, so you have 40 in 40 fields that you just filmed and each of those fields has 30 cells, then you have to sit down with each one of those movies and look at each one of those cells in that movie.So it takes a really long time to do data analysis. And that's, so it takes a week to analyze data that it took you two days to collect. So there's a, that's a very big obstacle in terms of gathering lots of data.So it's not, while it's high throughput data collection, it's not high throughput analysis. So what would you make to make this experiment really high throughput? So our lab is in the process of developing a program that does the data analysis automatically.And it's a pretty decent program. It's not perfect. The human eye is always better, but it's getting there.So What are the interesting application of this experiment? Maybe other fields you can mention? Besides cell division?You mean for the, oh, for the live cell imaging? Yes.Well, you can do cell motility assays. You can, depending on the, the microscopy that's involved, you can, you know, look at how cells, you could look at tumor development if you really wanted to.But there, you, you're, if as long as you have the right imaging set up, you can, you're pretty much not limited in terms of anything. Our scope happens to be just a wide field and we use 20 by 20 x objective. So it's a pretty low resolution set up, but that's sufficient for what we need to see.So there are, but there definitely aren't, you wouldn't be limited. Anything that has any dynamic kind of experiment, which is biology, it would be, would really benefit from lifestyle imaging. So calcium imaging, although you couldn't do it on our apparatus, that's a live cell.You definitely need live cell imaging for that. Like I said, patient assays, motility assays, those kinds of things would really benefit from live cell imaging. Would you like to tell a few words about your previous experience?How long do you work on these techniques? What do you you work on before? Wow.So in my PhD I didn't work.I did a lot of confocal microscopy, but no lifestyle imaging. And so during my postdoc I was, I helped Dr.King get this apparatus that, that we just used to set up these fragment, get that up and running. And, and so during my postdoc, I had a lot of experience with both widefield with TimeLapse imaging on our scope, which is the widefield and also TimeLapse imaging with confocal microscopy.And I would say that it's really powerful. You get a lot of information, but it's not easy to get working perfectly. So it really requires a lot of attention and a lot of attention to details at every little step of the process.And, and then you still have problems. So it's a tough application, but you can really get, if, if it's what you need to have to, to study your problem, your scientific problem, then it, it's invaluable in that respect, but it's tough. So find someone who knows what they're doing and use them.That's my advice. So good.

A lungo termine Imaging cellule di mammifero utilizzando Wide-Field Microscopia

Video Bioinformatics Analysis of Human Embryonic Stem Cell Colony Growth

Because video data are complex and are comprised of many images, mining information from video material is difficult to do without the aid of computer software.  Video bioinformatics is a powerful quantitative approach for extracting spatio-temporal data from video images using computer software to perform dating mining and analysis. In this article, we introduce a video bioinformatics method for quantifying the growth of human embryonic stem cells (hESC) by analyzing time-lapse videos collected in a Nikon BioStation CT incubator equipped with a camera for video imaging. In our experiments, hESC colonies that were attached to Matrigel were filmed for 48 hours in the BioStation CT.  To determine the rate of growth of these colonies, recipes were developed using CL-Quant software which enables users to extract various types of data from video images.  To accurately evaluate colony growth, three recipes were created. The first segmented the image into the colony and background, the second enhanced the image to define colonies throughout the video sequence accurately, and the third measured the number of pixels in the colony over time.  The three recipes were run in sequence on video data collected in a BioStation CT to analyze the rate of growth of individual hESC colonies over 48 hours. To verify the truthfulness of the CL-Quant recipes, the same data were analyzed manually using Adobe Photoshop software. When the data obtained using the CL-Quant recipes and Photoshop were compared, results were virtually identical, indicating the CL-Quant recipes were truthful. The method described here could be applied to any video data to measure growth rates of hESC or other cells that grow in colonies. In addition, other video bioinformatics recipes can be developed in the future for other cell processes such as migration, apoptosis, and cell adhesion.  

Video bioinformatics is the automated processing, analysis, understanding, and data mining of biological spatio-temporal data extracted from microscopic videos. The purpose of this article is to demonstrate a method for measuring human embryonic stem cell colony growth using a video bioinformatics method.

Video Bioinformatica Analisi delle embrionali umane crescita Colony cellule staminali

Because video data are complex and are comprised of many images, mining information from video material is difficult to do without the aid of computer ...

MISSION esiRNA for RNAi Screening in Mammalian Cells

RNA interference (RNAi) is a basic cellular mechanism for the control of gene expression. RNAi is induced by short double-stranded RNAs also known as small interfering RNAs (siRNAs). The short double-stranded RNAs originate from longer double stranded precursors by the activity of Dicer, a protein of the RNase III family of endonucleases. The resulting fragments are components of the RNA-induced silencing complex (RISC), directing it to the cognate target mRNA. RISC cleaves the target mRNA thereby reducing the expression of the encoded protein1,2,3. RNAi has become a powerful and widely used experimental method for loss of gene function studies in mammalian cells utilizing small interfering RNAs.
Currently two main methods are available for the production of small interfering RNAs. One method involves chemical synthesis, whereas an alternative method employs endonucleolytic cleavage of target specific long double-stranded RNAs by RNase III in vitro. Thereby, a diverse pool of siRNA-like oligonucleotides is produced which is also known as endoribonuclease-prepared siRNA or esiRNA. A comparison of efficacy of chemically derived siRNAs and esiRNAs shows that both triggers are potent in target-gene silencing. Differences can, however, be seen when comparing specificity. Many single chemically synthesized siRNAs produce prominent off-target effects, whereas the complex mixture inherent in esiRNAs leads to a more specific knockdown10.
In this study, we present the design of genome-scale MISSION esiRNA libraries and its utilization for RNAi screening exemplified by a DNA-content screen for the identification of genes involved in cell cycle progression. We show how to optimize the transfection protocol and the assay for screening in high throughput. We also demonstrate how large data-sets can be evaluated statistically and present methods to validate primary hits. Finally, we give potential starting points for further functional characterizations of validated hits.

Here we use a human esiRNA library in a high-throughput screen for genes involved in cell division. We demonstrate how to set up and conduct an esiRNA screens, as well as how to analyze and validate the results.

EsiRNA MISSIONE per lo screening RNAi in cellule di mammifero

RNA interference (RNAi) is a basic cellular mechanism for the control of gene expression. RNAi is induced by short double-stranded RNAs also known as ...

Analysis of Cell Cycle Position in Mammalian Cells

The regulation of cell proliferation is central to tissue morphogenesis during the development of multicellular organisms. Furthermore, loss of control of cell proliferation underlies the pathology of diseases like cancer. As such there is great need to be able to investigate cell proliferation and quantitate the proportion of cells in each phase of the cell cycle. It is also of vital importance to indistinguishably identify cells that are replicating their DNA within a larger population. Since a cell&prime;s decision to proliferate is made in the G1 phase immediately before initiating DNA synthesis and progressing through the rest of the cell cycle, detection of DNA synthesis at this stage allows for an unambiguous determination of the status of growth regulation in cell culture experiments.
DNA content in cells can be readily quantitated by flow cytometry of cells stained with propidium iodide, a fluorescent DNA intercalating dye. Similarly, active DNA synthesis can be quantitated by culturing cells in the presence of radioactive thymidine, harvesting the cells, and measuring the incorporation of radioactivity into an acid insoluble fraction. We have considerable expertise with cell cycle analysis and recommend a different approach. We Investigate cell proliferation using bromodeoxyuridine/fluorodeoxyuridine (abbreviated simply as BrdU) staining that detects the incorporation of these thymine analogs into recently synthesized DNA. Labeling and staining cells with BrdU, combined with total DNA staining by propidium iodide and analysis by flow cytometry1 offers the most accurate measure of cells in the various stages of the cell cycle. It is our preferred method because it combines the detection of active DNA synthesis, through antibody based staining of BrdU, with total DNA content from propidium iodide. This allows for the clear separation of cells in G1 from early S phase, or late S phase from G2/M. Furthermore, this approach can be utilized to investigate the effects of many different cell stimuli and pharmacologic agents on the regulation of progression through these different cell cycle phases.
In this report we describe methods for labeling and staining cultured cells, as well as their analysis by flow cytometry. We also include experimental examples of how this method can be used to measure the effects of growth inhibiting signals from cytokines such as TGF-&beta;1, and proliferative inhibitors such as the cyclin dependent kinase inhibitor, p27KIP1. We also include an alternate protocol that allows for the analysis of cell cycle position in a sub-population of cells within a larger culture5. In this case, we demonstrate how to detect a cell cycle arrest in cells transfected with the retinoblastoma gene even when greatly outnumbered by untransfected cells in the same culture. These examples illustrate the many ways that DNA staining and flow cytometry can be utilized and adapted to investigate fundamental questions of mammalian cell cycle control.

Determining the cell cycle position of a population of cells, or understanding how signals affect proliferation, can be readily measured by flow cytometry using this protocol. We report a simple experimental approach to staining cells and quantifying their position in the cell cycle.

Analisi della posizione ciclo cellulare nelle cellule di mammifero

The regulation of cell proliferation is central to tissue morphogenesis during the development of multicellular organisms. Furthermore, loss of control of ...

Determination of Mammalian Cell Counts, Cell Size and Cell Health Using the Moxi Z Mini Automated Cell Counter

Particle and cell counting is used for a variety of applications including routine cell culture, hematological analysis, and industrial controls1-5. A critical breakthrough in cell/particle counting technologies was the development of the Coulter technique by Wallace Coulter over 50 years ago. The technique involves the application of an electric field across a micron-sized aperture and hydrodynamically focusing single particles through the aperture. The resulting occlusion of the aperture by the particles yields a measurable change in electric impedance that can be directly and precisely correlated to cell size/volume. The recognition of the approach as the benchmark in cell/particle counting stems from the extraordinary precision and accuracy of its particle sizing and counts, particularly as compared to manual and imaging based technologies (accuracies on the order of 98% for Coulter counters versus 75-80% for manual and vision-based systems). This can be attributed to the fact that, unlike imaging-based approaches to cell counting, the Coulter Technique makes a true three-dimensional (3-D) measurement of cells/particles which dramatically reduces count interference from debris and clustering by calculating precise volumetric information about the cells/particles. Overall this provides a means for enumerating and sizing cells in a more accurate, less tedious, less time-consuming, and less subjective means than other counting techniques6.
Despite the prominence of the Coulter technique in cell counting, its widespread use in routine biological studies has been prohibitive due to the cost and size of traditional instruments. Although a less expensive Coulter-based instrument has been produced, it has limitations as compared to its more expensive counterparts in the correction for "coincidence events" in which two or more cells pass through the aperture and are measured simultaneously. Another limitation with existing Coulter technologies is the lack of metrics on the overall health of cell samples. Consequently, additional techniques must often be used in conjunction with Coulter counting to assess cell viability. This extends experimental setup time and cost since the traditional methods of viability assessment require cell staining and/or use of expensive and cumbersome equipment such as a flow cytometer.
The Moxi Z mini automated cell counter, described here, is an ultra-small benchtop instrument that combines the accuracy of the Coulter Principle with a thin-film sensor technology to enable precise sizing and counting of particles ranging from 3-25 microns, depending on the cell counting cassette used. The M type cassette can be used to count particles from with average diameters of 4 - 25 microns (dynamic range 2 - 34 microns), and the Type S cassette can be used to count particles with and average diameter of 3 - 20 microns (dynamic range 2 - 26 microns). Since the system uses a volumetric measurement method, the 4-25 microns corresponds to a cell volume range of 34 - 8,180 fL and the 3 - 20 microns corresponds to a cell volume range of 14 - 4200 fL, which is relevant when non-spherical particles are being measured. To perform mammalian cell counts using the Moxi Z, the cells to be counted are first diluted with ORFLO or similar diluent. A cell counting cassette is inserted into the instrument, and the sample is loaded into the port of the cassette. Thousands of cells are pulled, single-file through a "Cell Sensing Zone" (CSZ) in the thin-film membrane over 8-15 seconds. Following the run, the instrument uses proprietary curve-fitting in conjunction with a proprietary software algorithm to provide coincidence event correction along with an assessment of overall culture health by determining the ratio of the number of cells in the population of interest to the total number of particles. The total particle counts include shrunken and broken down dead cells, as well as other debris and contaminants. The results are presented in histogram format with an automatic curve fit, with gates that can be adjusted manually as needed.
Ultimately, the Moxi Z enables counting with a precision and accuracy comparable to a Coulter Z2, the current gold standard, while providing additional culture health information. Furthermore it achieves these results in less time, with a smaller footprint, with significantly easier operation and maintenance, and at a fraction of the cost of comparable technologies.

The Moxi Z miniature automated cell counter is a novel instrument that combines the Coulter Principle with patented thin-film sensor technology and a proprietary software algorithm to perform sizing and counting of a broad size range of particles as well as to determine the overall health of monodisperse mammalian cell cultures. This protocol describes the use of this instrument for counting and assessing the health of cell cultures.

Determinazione del conteggio delle cellule dei mammiferi, le dimensioni delle cellule e la salute delle cellule utilizzando il Moxi Z Mini contaglobuli automatizzato

Particle and cell counting is used for a variety of applications including routine cell culture, hematological analysis, and industrial controls1-5. A ...

Alternative Cultures for Human Pluripotent Stem Cell Production, Maintenance, and Genetic Analysis

Human pluripotent stem cells (hPSCs) hold great promise for regenerative medicine and biopharmaceutical applications. Currently, optimal culture and efficient expansion of large amounts of clinical-grade hPSCs are critical issues in hPSC-based therapies. Conventionally, hPSCs are propagated as colonies on both feeder and feeder-free culture systems. However, these methods have several major limitations, including low cell yields and generation of heterogeneously differentiated cells. To improve current hPSC culture methods, we have recently developed a new method, which is based on non-colony type monolayer (NCM) culture of dissociated single cells. Here, we present detailed NCM protocols based on the Rho-associated kinase (ROCK) inhibitor Y-27632. We also provide new information regarding NCM culture with different small molecules such as Y-39983 (ROCK I inhibitor), phenylbenzodioxane (ROCK II inhibitor), and thiazovivin (a novel ROCK inhibitor). We further extend our basic protocol to cultivate hPSCs on defined extracellular proteins such as the laminin isoform 521 (LN-521) without the use of ROCK inhibitors. Moreover, based on NCM, we have demonstrated efficient transfection or transduction of plasmid DNAs, lentiviral particles, and oligonucleotide-based microRNAs into hPSCs in order to genetically modify these cells for molecular analyses and drug discovery. The NCM-based methods overcome the major shortcomings of colony-type culture, and thus may be suitable for producing large amounts of homogeneous hPSCs for future clinical therapies, stem cell research, and drug discovery.

Here, we present human pluripotent stem cell (hPSC) culture protocols, based on non-colony type monolayer (NCM) growth of dissociated single cells. This new method, utilizing Rho-associated kinase inhibitors or the laminin isoform 521 (LN-521), is suitable for producing large amounts of homogeneous hPSCs, genetic manipulation, and drug discovery.

Le colture per pluripotenti umane alternative staminali produzione di celle, manutenzione e analisi genetica

Human pluripotent stem cells (hPSCs) hold great promise for regenerative medicine and biopharmaceutical applications. Currently, optimal culture and ...

Measurement of Heme Synthesis Levels in Mammalian Cells

Heme serves as the prosthetic group for a wide variety of proteins known as hemoproteins, such as hemoglobin, myoglobin and cytochromes. It is involved in various molecular and cellular processes such as gene transcription, translation, cell differentiation and cell proliferation. The biosynthesis levels of heme vary across different tissues and cell types and is altered in diseased conditions such as anemia, neuropathy and cancer. This technique uses [4-14C] 5-aminolevulinic acid ([14C] 5-ALA), one of the early precursors in the heme biosynthesis pathway to measure the levels of heme synthesis in mammalian cells. This assay involves incubation of cells with [14C] 5-ALA followed by extraction of heme and measurement of the radioactivity incorporated into heme. This procedure is accurate and quick. This method measures the relative levels of heme biosynthesis rather than the total heme content. To demonstrate the use of this technique the levels of heme biosynthesis were measured in several mammalian cell lines.

Altered intracellular heme levels are associated with common diseases such as cancer. Thus, there is a need to measure heme biosynthesis levels in diverse cells. The goal of this protocol is to provide a fast and sensitive method to measure and compare the levels of heme synthesis in different cells.

La misurazione dei livelli Heme sintesi in cellule di mammifero

Heme serves as the prosthetic group for a wide variety of proteins known as hemoproteins, such as hemoglobin, myoglobin and cytochromes. It is involved in ...

Generation of Genomic Deletions in Mammalian Cell Lines via CRISPR/Cas9

The prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9 system may be re-purposed for site-specific eukaryotic genome engineering. CRISPR/Cas9 is an inexpensive, facile, and efficient genome editing tool that allows genetic perturbation of genes and genetic elements. Here we present a simple methodology for CRISPR design, cloning, and delivery for the production of genomic deletions. In addition, we describe techniques for deletion, identification, and characterization. This strategy relies on cellular delivery of a pair of chimeric single guide RNAs (sgRNAs) to create two double strand breaks (DSBs) at a locus in order to delete the intervening DNA segment by non-homologous end joining (NHEJ) repair. Deletions have potential advantages as compared to single-site small indels given the efficiency of biallelic modification, ease of rapid identification by PCR, predictability of loss-of-function, and utility for the study of non-coding elements. This approach can be used for efficient loss-of-function studies of genes and genetic elements in mammalian cell lines.

CRISPR/Cas9 is a robust system to produce disruption of genes and genetic elements. Here we describe a protocol for the efficient creation of genomic deletions in mammalian cell lines using CRISPR/Cas9.

Generazione di Genomic eliminazioni in linee cellulari di mammiferi via CRISPR / Cas9

The prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9 system may be re-purposed for site-specific ...

Maintenance of a Drosophila melanogaster Population Cage

Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life cycle of Drosophila enables collection of large quantities of material from embryos, larvae, pupae and adult flies, in a synchronized way, at a low economic cost. A major strategy for propagating large numbers of flies is the use of a fly population cage. This useful and common tool in the Drososphila community is an efficient way to regularly produce milligrams to tens of grams of embryos, depending on uniformity of developmental stage desired. While a population cage can be time consuming to set up, maintaining a cage over months takes much less time and enables rapid collection of biological material in a short period. This paper describes a detailed and flexible protocol for the maintenance of a Drosophila melanogaster population cage, starting with 1.5 g of harvested material from the previous cycle.

Maintenance of a Drosophila melanogaster Population Cage

This manuscript reports a detailed protocol for culturing, on a regular basis, a population of Drosophila melanogaster using a fly population cage.

Mantenimento di un<em&gt; Drosophila melanogaster</em&gt; Cage Popolazione

Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life ...