Vorremmo ringraziare il Dott. Vesper Fe Marie Ramos per la lettura critica del manoscritto. Questo lavoro è stato sostenuto dal National Center for Research Resources (P20 RR0115635-6, C06-01 e RR17417 G20RR024001) e l&#39;Istituto Nazionale per la Neurological Disorder and Stroke (2R01 NS052609).

1. Preparazione dell&#39;apparecchiatura <ol><li> Utilizzare un 3000 Misonix o Misonix 4000 sonicatore (Farmingdale, NY) collegato ad un bagno di Thermo Electron Neslab EX-7 acqua (Newington, NH) per mantenere una temperatura costante di 37 ° C. Sonicare i campioni in 200 ml a pareti sottili strisce di provette PCR con tappi a cupola ottenuti da Thermo Scientific (Waltham, MA). </li><li> Un sonicatore nuovo richiede un periodo di &quot;rodaggio&quot; di funzionamento continuo 9. A due mesi il periodo di rodaggio è costituito da un 40-secondo scoppio sonicazione e 10 minuti cicli di incubazione con il livello di ampiezza impostato su 10. Si dovrebbero osservare erosione tutta la superficie della micropiastra titanio tromba (figura 1, pannello B). L&#39;acqua che circola sarà bianca, torbida, a causa dell&#39;erosione della micropiastra titanio corno. Sostituire questa acqua al giorno. </li><li> L&#39;amplificazione di PrP Sc varierà in tutto il corno micropiastra. La migliore efficienza di amplificazione PrP Sc può essere ottenuto entroun raggio di 5 cm dal centro del corno micropiastra (vedi figura 1, pannello C). </li><li> Un giro di PMCA consiste 144 cicli. Ogni ciclo è composto di 5 sonicazione secondi e 10 minuti di incubazione. Ciò richiederà a circa 24 ore per ogni turno di PMCA. </li><li> La potenza della sonicazione, visualizzata sul pannello di controllo del sonicatore, la varia con il numero di provette PCR presenti nel rack del sonicatore e la temperatura dell&#39;acqua circolante dal bagno. Garantire che l&#39;acqua è equilibrata a 37 ° C, e non riempire più del 30% del portaprovette del sonicatore (figura 1, pannello C). Allargare le provette PCR tramite la sirena micropiastra. Avere almeno una fila di spazio vuoto tra le strisce di provette PCR e permettono non più di quattro tubi collegati insieme per striscia (figura 1, pannello C). </li><li> La forza di sonicazione è fondamentale per una amplificazione di successo ceppo prione. Mentre sonicating, regolare l&#39;ampiezza di avere una potenzacompresa tra 155 ~ 170 watt. Nel nostro laboratorio il livello di potenza è impostato su sei e sette per il 3000 Misonix Misonix e 4000, rispettivamente. </li><li> Usare acqua distillata nel bagno d&#39;acqua per evitare l&#39;accumulo di macchie d&#39;acqua dura. Sostituire questo settimanale acqua. Durante i cicli di incubazione e sonicazione, condensa si verifica all&#39;interno del coperchio corno micropiastra. Per evitare la formazione di condensa, allegare un piccolo pad termico acquario all&#39;inizio della scatola contenitore del sonicatore come mostrato in figura 1, il pannello A. </li></ol> 2. Preparazione dei campioni <ol><li> Tutte le procedure che coinvolgono animali sono state approvate dal Animal Care Università Creighton istituzionale e uso Comitato e rispettare la Guida per la cura e l&#39;uso di animali da laboratorio. Prima di qualsiasi raccolta del tessuto, l&#39;animale deve essere anestetizzati e perfusi con transcardiaca ghiacciata fosfato soluzione salina tamponata con 5 mM EDTA a pH 7,4 per rimuovere il sangue dal cervello ed evitare l&#39;inibizione dellaReazione PMCA di sangue 7. Raccogliere tessuti animali rapidamente usando tecniche asettiche e dispongono di strumenti di dissezione dedicati per ogni ceppo del prione. Dopo la dissezione, posizionare il tessuto in una provetta da 1,5 ml microcentrifuga, flash congelare il ghiaccio secco, e conservarlo a -80 ° C fino omogeneizzazione. </li><li> Per preparare il substrato PMCA (PrP C) soluzione, omogeneizzare un cervello infetto criceto (ONU BH) per un 10% peso / volume (w / v) con soluzione di tampone ghiacciato di conversione (vedere parte 3) utilizzando una mola tessuto Tenbroeck. Mentre omogeneizzazione, fare attenzione a non far entrare aria all&#39;interno della smerigliatrice per evitare eccessiva formazione di schiuma della soluzione. Chiarire la soluzione per centrifugazione a 500 xg per 30 sec e un&#39;aliquota del surnatante in provette per microcentrifuga 1,5 ml. Conservare a -80 ° C fino ad ulteriore utilizzo. </li><li> Per preparare il seme PMCA (PrP Sc) soluzione, omogeneizzare un materiale infettivo (linfonodi cervello, milza, altri tessuti, o suolo contaminato) ad un 10% w / v soluzione con wate ghiacciatar e aliquota della soluzione in 0,6 ml microprovette. Conservare a -80 ° C fino ad ulteriore utilizzo. </li></ol> 3. Preparazione del buffer di conversione <ol><li> Pesare 0,5093 g di Triton X-100 in un pallone tarato da 50 ml (risultato una concentrazione finale di 1% Triton X-100) (Sigma-Aldrich GmbH, Steinheim, Germania). </li><li> Aggiungere un completo proteasi Tablet (Roche Diagnostics GmbH, Mannheim, Germania). </li><li> Aggiungere 0,0931 g di EDTA (questo si tradurrà in una concentrazione finale di 5 mM EDTA) (Mallinckrodt Baker Inc., Phillipsburg, NJ). </li><li> Regolare il pH a 7,4 con NaOH 1N. </li><li> Regolare il volume di 50 ml con fosfato di Dulbecco Buffered Saline (DPBS) (Mediatech Inc., Manassas, VA). </li><li> Filtrare la soluzione attraverso membrana da 0,45 micron nitrocellulosa con un apparato di filtrazione sotto vuoto. Il buffer di conversione può essere conservato a 4 ° C per non più di un mese. </li></ol> 4. L&#39;amplificazione dei ceppi di prioni tramite PMCA <ol><li>Diluire il seme PMCA nel substrato PMCA con un rapporto di 01:20 (mix ossia 5 microlitri del seme PMCA e 95 pl di substrato PMCA) in una provetta PCR. Rimuovere e conservare una aliquota 15 microlitri a -80 ° C per il controllo unsonicated; questo controllo unsonicated verrà utilizzato per quantificare l&#39;amplificazione PrP Sc via proteinasi K (PK) digestione seguita da Western blot (WB) analisi. Un ulteriore controllo unsonicated potrebbe essere generato ponendo una seconda aliquota di 15 microlitri a 37 ° C per tutta la durata della reazione PMCA. Un minimo di tre ripetizioni è richiesto per fini statistici. </li><li> Oggetto del resto del campione (70 microlitri) di un ciclo di PMCA come rappresentato in figura 1, pannello A. Agitare tubi ogni 5 ore per evitare la formazione di condensa sul coperchio a cupola del tubo PCR. </li><li> Provette del campione deve essere centrifugati e delicatamente vortex (facendo attenzione che la soluzione non vanno nel tappo a cupola) prima di aprire dopo ogni intervento per garantire la omogenizzazioneeneity ed evitare potenziali contaminazioni. </li><li> Per seriale PMCA (sPMCA) di ceppi brevi periodo di incubazione (cioè HY TME, HaCWD o 263K), diluire il materiale sonicata in un rapporto di 01:20 trasferendo 5 microlitri del campione da sonicato rotonda in 95 pl di uninfected fresca omogenato cerebrale (Figura 2, pannello B). </li><li> Per sPMCA di ceppi lungo periodo di incubazione (cioè DY TME, 139H, 22CH, 22AH, o ME7H), diluire il materiale sonicata in un rapporto di 1:1, trasferendo 50 microlitri del campione da sonicato rotonda in 50 pl di uninfected fresca omogenato cerebrale (Figura 2, pannello B). </li><li> Rimuovere due aliquote da 15 pl della miscela precedentemente diluito con ultrasuoni (passi da 4,4 o 4,5) e memorizzare uno di loro a -80 ° C e l&#39;altro a 37 ° C (soluzioni di controllo unsonicated per PMCA round). Sottoporre i resti di un giro PMCA due. </li><li> Questa procedura può essere ripetuta indefinitamente. Nel nostro laboratorio, abbiamohanno effettuato fino a quindici giri PMCA, con le proprietà di deformazione è rimasto immodificato. </li><li> PK digerire i campioni. Per una tipica WB, mescolare 5 ml di PK 80 ug / ml a 5 l di campione (questa soluzione avrà una concentrazione finale di PK 40 mcg / ml) e incubare a 37 ° C per un&#39;ora. Aggiungere 10 ml di tampone di gel carico. Bollire questa soluzione per 10 min. Lasciate raffreddare la soluzione e caricare 10 microlitri nel gel. </li><li> Per calcolare il successo di amplificazione eseguire un&#39;analisi WB sulle PK-digerito campioni per stimare la quantità di amplificato PrP Sc confrontandole con uno, i controlli unsonicated 20,21 Figura 2, Pannello C o in valori di PK-digerito ricombinante PrP. </li></ol> 5. Evitare contaminazione incrociata Passaggi critici devono essere prese per ridurre al minimo la contaminazione incrociata e l&#39;insorgenza di falsi positivi dovuti alla formazione de novo di prodotti resistenti proteasi. </p&gt; <ol><li> Utilizzare un set dedicato di strumenti di dissezione (cioè pinze, pinzette, forbici) per la raccolta del campione per ogni ceppo del prione. </li><li> Prima di omogeneizzazione cervelli infetti da utilizzare come substrato PMCA, pulire le pipette con 1% di candeggina. Immergere il sonicatore di portaprovette PCR, omogeneizzatori tessuti, PCR e scaffalature di stoccaggio tubo con 1% di candeggina per 10 minuti e risciacquare abbondantemente con acqua distillata. </li><li> Coprire l&#39;area di lavoro con una nuova Versi-Dry Soaker Lab ogni volta che un nuovo campione deve essere omogeneizzato, un nuovo esperimento PMCA deve essere preparata, o quando aliquotandolo tra un round sPMCA. </li><li> Utilizzare guanti nuovi di volta in volta nuovi campioni sono trattati (in particolare durante il trasferimento di aliquote tra un round sPMCA). </li><li> Utilizzare raffiche brevi sonicazione per ogni ciclo PMCA. Cicli su 5 sonicazione sec combinata con 10 minuti di incubazione è sufficiente per amplificare prioni senza generare de novo PrPSc 1,20,21,23,24. Come altri laboratori hanno mostrato, aumentando latempo di sonicazione, aumentando l&#39;ampiezza sonicazione, e aumentando il numero di cicli PMCA aumenta la probabilità di PrP Sc de novo formazione 2. </li></ol>

<ol>
	<li>Ayers, J. I., Schutt, C. R., Shikiya, R. A., Aguzzi, A., Kincaid, A. E., Bartz, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+strain-encoded+relationship+between+PrP+replication,+stability+and+processing+in+neurons+is+predictive+of+the+incubation+period+of+disease.">The strain-encoded relationship between PrP replication, stability and processing in neurons is predictive of the incubation period of disease.</a> PLoS pathogens. 7, e1001317 (2011).</li><li>Barria, M. A., Mukherjee, A., Gonzalez-Romero, D., Morales, R., Soto, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=De+novo+generation+of+infectious+prions+in+vitro+produces+a+new+disease+phenotype.">De novo generation of infectious prions in vitro produces a new disease phenotype.</a> PLoS Pathog. 5, e1000421 (2009).</li><li>Bessen, R. A., Marsh, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biochemical+and+physical+properties+of+the+prion+protein+from+two+strains+of+the+transmissible+mink+encephalopathy+agent.">Biochemical and physical properties of the prion protein from two strains of the transmissible mink encephalopathy agent.</a> J. Virol. 66, 2096-2101 (1992).</li><li>Bessen, R. A., Marsh, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distinct+PrP+properties+suggest+the+molecular+basis+of+strain+variation+in+transmissible+mink+encephalopathy.">Distinct PrP properties suggest the molecular basis of strain variation in transmissible mink encephalopathy.</a> J. Virol. 68, 7859-7868 (1994).</li><li>Bessen, R. A., Marsh, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+two+biologically+distinct+strains+of+transmissible+mink+encephalopathy+in+hamsters.">Identification of two biologically distinct strains of transmissible mink encephalopathy in hamsters.</a> J. Gen. Virol. 73, 329-334 (1992).</li><li>Castilla, J., Gonzalez-Romero, D., Saa, P., Morales, R., De Castro, J., Soto, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Crossing+the+species+barrier+by+PrP(Sc)+replication+in+vitro+generates+unique+infectious+prions.">Crossing the species barrier by PrP(Sc) replication in vitro generates unique infectious prions.</a> Cell. 134, 757-768 (2008).</li><li>Castilla, J., Morales, R., Saa, P., Barria, M., Gambetti, P., Soto, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-free+propagation+of+prion+strains.">Cell-free propagation of prion strains.</a> EMBO J. 27, 2557-2566 (2008).</li><li>Caughey, B., Raymond, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+scrapie-associated+form+of+PrP+is+made+from+a+cell+surface+precursor+that+is+both+protease-+and+phospholipase-sensitive.">The scrapie-associated form of PrP is made from a cell surface precursor that is both protease- and phospholipase-sensitive.</a> J. Biol. Chem. 266, 18217-18223 (1991).</li><li>Deleault, N. R., Harris, B. T., Rees, J. R., Supattapone, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+native+prions+from+minimal+components+in+vitro.">Formation of native prions from minimal components in vitro.</a> Proceedings of the National Academy of Sciences of the United States of America. 104, 9741-9746 (2007).</li><li>Dickinson, A. G., Fraser, H., Meikle, V. M., Outram, G. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Competition+between+different+scrapie+agents+in+mice.">Competition between different scrapie agents in mice.</a> Nat. New Biol. 237, 244-245 (1972).</li><li>Gonzalez-Romero, D., Barria, M. A., Leon, P., Morales, R., Soto, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+infectious+prions+in+urine.">Detection of infectious prions in urine.</a> FEBS Lett. 582, 3161-3166 (2008).</li><li>Green, K. M., Castilla, J., Seward, T. S., Napier, D. L., Jewell, J. E., Soto, C., Telling, G. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accelerated+high+fidelity+prion+amplification+within+and+across+prion+species+barriers.">Accelerated high fidelity prion amplification within and across prion species barriers.</a> PLoS Pathog. 4, e1000139 (2008).</li><li>Hadlow, W. J., Race, R. E., Kennedy, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal+distribution+of+transmissible+mink+encephalopathy+virus+in+mink+inoculated+subcutaneously.">Temporal distribution of transmissible mink encephalopathy virus in mink inoculated subcutaneously.</a> J. Virol. 61, 3235-3240 (1987).</li><li>Kocisko, D. A., Come, J. H., Priola, S. A., Chesebro, B., Raymond, G. J., Lansbury, P. T., Caughey, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-free+formation+of+protease-resistant+prion+protein.">Cell-free formation of protease-resistant prion protein.</a> Nature. 370, 471-474 (1994).</li><li>Kurt, T. D., Telling, G. C., Zabel, M. D., Hoover, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trans-species+amplification+of+PrP(CWD)+and+correlation+with+rigid+loop+170N.">Trans-species amplification of PrP(CWD) and correlation with rigid loop 170N.</a> Virology. 387, 3235-3240 (2009).</li><li>Maddison, B. C., Baker, C. A., Terry, L. A., Bellworthy, S. J., Thorne, L., Rees, H. C., Gough, K. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Environmental+sources+of+scrapie+prions.">Environmental sources of scrapie prions.</a> J. Virol. 84, 11560-11562 (2010).</li><li>Nichols, T. A., Pulford, B., Wyckoff, A. C., Meyerett, C., Michel, B., Gertig, K., Hoover, E. A., Jewell, J. E., Telling, G. C., Zabel, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+protease-resistant+cervid+prion+protein+in+water+from+a+CWD-endemic+area.">Detection of protease-resistant cervid prion protein in water from a CWD-endemic area.</a> Prion. 3, 171-183 (2009).</li><li>Prusiner, S. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+proteinaceous+infectious+particles+cause+scrapie.">Novel proteinaceous infectious particles cause scrapie.</a> Science. 216, 136-144 (1982).</li><li>Saborio, G. P., Permanne, B., Soto, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensitive+detection+of+pathological+prion+protein+by+cyclic+amplification+of+protein+misfolding.">Sensitive detection of pathological prion protein by cyclic amplification of protein misfolding.</a> Nature. 411, 810-813 (2001).</li><li>Saunders, S. E., Bartz, J. C., Vercauteren, K. C., Bartelt-Hunt, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+enzymatic+treatment+of+soil-bound+prions+effectively+inhibits+replication.">An enzymatic treatment of soil-bound prions effectively inhibits replication.</a> Appl. Environ. Microbiol. 77, 4313-4317 (2011).</li><li>Saunders, S. E., Shikiya, R. A., Langenfeld, K., Bartelt-Hunt, S. L., Bartz, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Replication+efficiency+of+soil-bound+prions+varies+with+soil+type.">Replication efficiency of soil-bound prions varies with soil type.</a> Journal of virology. , (2011).</li><li>Schutt, C. R., Bartz, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prion+interference+with+multiple+prion+isolates.">Prion interference with multiple prion isolates.</a> Prion. 2, 61-63 (2008).</li><li>Shikiya, R. A., Ayers, J. I., Schutt, C. R., Kincaid, A. E., Bartz, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Co-infecting+prion+strains+compete+for+a+limiting+cellular+resource.">Co-infecting prion strains compete for a limiting cellular resource.</a> Journal of. 84, 5706-5714 (2010).</li><li>Shikiya, R. A., Bartz, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+generation+of+high+titer+prions.">In vitro generation of high titer prions.</a> Journal of virology. , (2011).</li><li>Weber, P., Giese, A., Piening, N., Mitteregger, G., Thomzig, A., Beekes, M., Kretzschmar, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+genuine+prion+infectivity+by+serial+PMCA.">Generation of genuine prion infectivity by serial PMCA.</a> Veterinary microbiology. 123, 346-357 (2007).</li></ol>

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Le sfide di amplificazione proteine ​​prioniche infettive sono i periodi di incubazione lunghi e le spese in esperimenti in vivo. La tecnica PMCA è una soluzione economica per amplificare agenti prioni infettivi. Diversi laboratori hanno confermato la capacità di PMCA di amplificare accuratamente ceppi di prioni in vitro 7, 9, 12, 14, 19,24. Malattie da prioni possono essere trasmessi tra le specie. Bessen e Marsh sono effettivamente inoculato cric...

<table border="1"><tbody><tr><td> Reagente / attrezzature </td><td> Fabbricante </td><td> Cat. Numero </td></tr><tr><td> Misonix 3000 </td><td> Misonix </td><td> S-3000 </td></tr><tr><td> Misonix 4000 </td><td> Misonix </td><td> S-4000 </td></tr><tr><td> Tenbroeck Tissue Grinder </td><td> Kontes </td><td> 885000-0007 </td></tr><tr><td> Neslab Bagno EX-7 Acqua </td><td> Thermo Electron </td><td> Neslab EX-7 </td></tr><tr><td> PCR da 0,2 ml tubo strisce </td><td> Thermo Scientific </td><td> AB-0451 </td></tr><tr><td> Triton X-100 </td><td> Sigma Aldrich </td><td> T9284-100ML </td></tr><tr><td> Proteasi completo </td><td> Roche </td><td> 11 697 498 001 </td></tr><tr><td> EDTA </td><td> JT Baker </td><td> 4040-00 </td></tr><tr><td> DPBS </td><td> Mallinckrodt Baker Mediatech </td><td> 21-031-CV </td></tr><tr><td> Versi-Dry Lab Soakers </td><td> Fisher Scientific </td><td> 14 206 28 </td></tr><tr><td> Repti Therm Riscaldatore </td><td> Zoo Med Laboratories, Inc. </td><td> RH-4 </td></tr></tbody></table>

protein misfolding cyclic amplification of prions

I prioni sono gli agenti infettivi che causano l&#39;encefalopatia inevitabilmente fatale spongiforme trasmissibile (TSE) negli animali e nell&#39;uomo 9,18. La proteina prionica ha due isoforme distinte, non infettiva ospitante proteina codificata (PrP C) e la proteina infettiva (PrP Sc), una isoforma anormalmente piegato PrP-C 8. Una delle sfide di lavorare con agenti prioni è il lungo periodo di incubazione prima dello sviluppo dei sintomi clinici dopo l&#39;inoculazione ospite 13. Questo mandato tradizionalmente lunghi e costosi studi di saggi biologici animali. Inoltre, le proprietà biochimiche e biofisiche di PrP Sc sono poco caratterizzati per la loro particolare conformazione e gli stati di aggregazione. PrPSc può seme della conversione della PrP C e PrP Sc in vitro 14. PMCA è una tecnica in vitro che prende ADVAntage di questa capacità con cicli di sonicazione e di incubazione per la produzione di grandi quantità di PrP Sc, ad un ritmo accelerato, da un sistema che contiene una quantità eccessiva di PrP C e piccole quantità di seme PrP Sc 19. Questa tecnica ha dimostrato di ricapitolare in modo efficace la specificità di specie e la tensione di PrP Sc conversione da PrP C, per emulare ceppo interferenze prioni, e di amplificare livelli molto bassi di PrP Sc da tessuti infetti, fluidi, e campioni ambientali 6,7,16, 23. Questa carta dettagli del protocollo di PMCA, comprese le raccomandazioni per minimizzare la contaminazione, la generazione di risultati coerenti, e quantificare tali risultati. Discutiamo anche diverse applicazioni PMCA, compresa la produzione e la caratterizzazione dei ceppi di prioni infettivi, ceppo interferenza prione, e l&#39;individuazione dei prioni nell&#39;ambiente.

Misfolding amplificazione proteina ciclica (PMCA) è utilizzato per amplificare PrP Sc in vitro 7, 12, 14, 19, 24. Un successo PrP Sc amplificazione è indicato da un aumento di intensità banda su Western blot della PK-resistente proteina prionica (migrazione tra 19 e 30 kDa per criceto derivati ​​ceppi di prioni) come mostrato in Figura 3. L&#39;aumento della sua intensità band dopo PMCA indica amplificazione del PK-materiale resistente PrPSc. ...

Watch this Scientific Journal Video about Protein Misfolding Cyclic Amplification of Prions at JoVE.com

Protein Misfolding Cyclic Amplification of Prions

Misfolding amplificazione proteina ciclica (PMCA) è un test in vitro per lo studio della conversione prionica e barriere deformazione e specie. Può anche essere usato come un test di rilevazione prione.

Proteine ​​ciclica Amplificazione misfolding di prioni

Prions  are infectious agents that cause the inevitably fatal transmissible spongiform  encephalopathy (TSE) in animals and humans9,18. The prion protein ...

protein-misfolding-cyclic-amplification-of-prions

Research

JoVE Journal

Immunology and Infection

19.4K Views.  University of Nebraska at Lincoln. Misfolding amplificazione proteina ciclica (PMCA) è un test in vitro per lo studio della conversione prionica e barriere deformazione e specie. Può anche essere usato come un test di rilevazione prione.

Video: Protein Misfolding Cyclic Amplification of Prions

Procedures for Identifying Infectious Prions After Passage Through the Digestive System of an Avian Species

Infectious prion (PrPRes) material is likely the cause of fatal, neurodegenerative transmissible spongiform encephalopathy (TSE) diseases1. Transmission of TSE diseases, such as chronic wasting disease (CWD), is presumed to be from animal to animal2,3 as well as from environmental sources4-6. Scavengers and carnivores have potential to translocate PrPRes material through consumption and excretion of CWD-contaminated carrion. Recent work has documented passage of PrPRes material through the digestive system of American crows (Corvus brachyrhynchos), a common North American scavenger7.
We describe procedures used to document passage of PrPRes material through American crows. Crows were gavaged with RML-strain mouse-adapted scrapie and their feces were collected 4 hr post gavage. Crow feces were then pooled and injected intraperitoneally into C57BL/6 mice. Mice were monitored daily until they expressed clinical signs of mouse scrapie and were thereafter euthanized. Asymptomatic mice were monitored until 365 days post inoculation. Western blot analysis was conducted to confirm disease status. Results revealed that prions remain infectious after traveling through the digestive system of crows and are present in the feces, causing disease in test mice.

Scavengers have potential to translocate infectious transmissible spongiform encephalopathy prions in their feces to disease-free areas. We detail methods used to determine if mouse-adapted scrapie prions remain infectious after passage though the digestive tract of American crows (Corvus brachyrhynchos), a common consumer of dead animals.

Procedure per l&#39;identificazione Infettive prioni dopo il passaggio attraverso l&#39;apparato digerente di una specie aviaria

Infectious prion (PrPRes) material is likely the cause of fatal, neurodegenerative transmissible spongiform encephalopathy (TSE) diseases1. Transmission ...

Ricerca

Immunologia e infezioni

Demonstrating a Multi-drug Resistant Mycobacterium tuberculosis Amplification Microarray

Simplifying microarray workflow is a necessary first step for creating MDR-TB microarray-based diagnostics that can be routinely used in lower-resource environments. An amplification microarray combines asymmetric PCR amplification, target size selection, target labeling, and microarray hybridization within a single solution and into a single microfluidic chamber. A batch processing method is demonstrated with a 9-plex asymmetric master mix and low-density gel element microarray for genotyping multi-drug resistant Mycobacterium tuberculosis (MDR-TB). The protocol described here can be completed in 6 hr and provide correct genotyping with at least 1,000 cell equivalents of genomic DNA. Incorporating on-chip wash steps is feasible, which will result in an entirely closed amplicon method and system. The extent of multiplexing with an amplification microarray is ultimately constrained by the number of primer pairs that can be combined into a single master mix and still achieve desired sensitivity and specificity performance metrics, rather than the number of probes that are immobilized on the array. Likewise, the total analysis time can be shortened or lengthened depending on the specific intended use, research question, and desired limits of detection. Nevertheless, the general approach significantly streamlines microarray workflow for the end user by reducing the number of manually intensive and time-consuming processing steps, and provides a simplified biochemical and microfluidic path for translating microarray-based diagnostics into routine clinical practice.

Demonstrating a Multi-drug Resistant Mycobacterium tuberculosis Amplification Microarray

An amplification microarray combines asymmetric PCR amplification and microarray hybridization into a single chamber, which significantly streamlines microarray workflow for the end user. Simplifying microarray workflow is a necessary first step for creating microarray-based diagnostics that can be routinely used in lower-resource environments.

Dimostrazione di un multi-resistente ai farmaci<em&gt; Mycobacterium tuberculosis</em&gt; Amplificazione Microarray

Simplifying microarray workflow is a necessary first step for creating MDR-TB microarray-based diagnostics that can be routinely used in lower-resource ...

Loop-mediated Isothermal Amplification (LAMP) Assays for the Species-specific Detection of Eimeria that Infect Chickens

Eimeria species parasites, protozoa which cause the enteric disease coccidiosis, pose a serious threat to the production and welfare of chickens. In the absence of effective control clinical coccidiosis can be devastating. Resistance to the chemoprophylactics frequently used to control Eimeria is common and sub-clinical infection is widespread, influencing feed conversion ratios and susceptibility to other pathogens such as Clostridium perfringens. Despite the availability of polymerase chain reaction (PCR)-based tools, diagnosis of Eimeria infection still relies almost entirely on traditional approaches such as lesion scoring and oocyst morphology, but neither is straightforward. Limitations of the existing molecular tools include the requirement for specialist equipment and difficulties accessing DNA as template. In response a simple field DNA preparation protocol and a panel of species-specific loop-mediated isothermal amplification (LAMP) assays have been developed for the seven Eimeria recognised to infect the chicken. We now provide a detailed protocol describing the preparation of genomic DNA from intestinal tissue collected post-mortem, followed by setup and readout of the LAMP assays. Eimeria species-specific LAMP can be used to monitor parasite occurrence, assessing the efficacy of a farm&#8217;s anticoccidial strategy, and to diagnose sub-clinical infection or clinical disease with particular value when expert surveillance is unavailable.

Loop-mediated Isothermal Amplification LAMP Assays for the Species-specific Detection of Eimeria that Infect Chickens

Diagnosis of Eimeria infection in chickens remains demanding. Parasite morphology- and host pathology-led approaches are commonly inconclusive, while molecular approaches based on PCR have proven demanding in cost and expertise. The aim of this protocol is to establish loop-mediated isothermal amplification (LAMP) as a straightforward molecular diagnostic for eimerian infection.

Isotermico di amplificazione (lampada) Assays Loop-mediata per rilevamento delle specie-specifica<em&gt; Eimeria</em&gt; Che infettano Polli

Eimeria species parasites, protozoa which cause the enteric disease coccidiosis, pose a serious threat to the production and welfare of chickens. In the ...

The Development of Lyophilized Loop-mediated Isothermal Amplification Reagents for the Detection of Coxiella burnetii

Coxiella burnetii, the agent causing Q fever, is an obligate intracellular bacterium. PCR based diagnostic assays have been developed for detecting C. burnetii DNA in cell cultures and clinical samples. PCR requires specialized equipment and extensive end user training, and therefore, it is not suitable for routine work especially in a resource-constrained area. We have developed a loop-mediated isothermal amplification (LAMP) assay to detect the presence of C. burnetii in patient samples. This method is performed at a single temperature around 60 &#176;C in a water bath or heating block. The sensitivity of this LAMP assay is very similar to PCR with a detection limit of about 25 copies per reaction. This report describes the preparation of the reaction using lyophilized reagents and visualization of results using hydroxynaphthol blue (HNB) or a UV lamp with fluorescent intercalating dye in the reaction. The LAMP reagents were lyophilized and stored at room temperature (RT) for one month without loss of detection sensitivity. This LAMP assay is particularly robust because the reaction mixture preparation does not involve complex steps. This method is ideal for use in resource-limited settings where Q fever is endemic.

The Development of Lyophilized Loop-mediated Isothermal Amplification Reagents for the Detection of Coxiella burnetii

We described here a simple loop-mediated isothermal amplification (LAMP) method using lyophilized reagents for the detection of C. burnetii in patient samples.

Lo sviluppo del liofilizzato Loop-mediate isotermici amplificazione reagenti per la rilevazione di<em&gt; Burnetii Coxiella</em

Coxiella burnetii, the agent causing Q fever, is an obligate intracellular bacterium. PCR based diagnostic assays have been developed for detecting C. ...

Real-time Quaking-induced Conversion Assay for Detection of CWD Prions in Fecal Material

The RT-QuIC technique is a sensitive in vitro cell-free prion amplification assay based mainly on the seeded misfolding and aggregation of recombinant prion protein (PrP) substrate using prion seeds as a template for the conversion. RT-QuIC is a novel high-throughput technique which is analogous to real-time polymerase chain reaction (PCR). Detection of amyloid fibril growth is based on the dye Thioflavin T, which fluoresces upon specific interaction with &#7526;-sheet rich proteins. Thus, amyloid formation can be detected in real time. We attempted to develop a reliable non-invasive screening test to detect chronic wasting disease (CWD) prions in fecal extract. Here, we have specifically adapted the RT-QuIC technique to reveal PrPSc seeding activity in feces of CWD infected cervids. Initially, the seeding activity of the fecal extracts we prepared was relatively low in RT-QuIC, possibly due to potential assay inhibitors in the fecal material. To improve seeding activity of feces extracts and remove potential assay inhibitors, we homogenized the fecal samples in a buffer containing detergents and protease inhibitors. We also submitted the samples to different methodologies to concentrate PrPSc on the basis of protein precipitation using sodium phosphotungstic acid, and centrifugal force. Finally, the feces extracts were tested by optimized RT-QuIC which included substrate replacement in the protocol to improve the sensitivity of detection. Thus, we established a protocol for sensitive detection of CWD prion seeding activity in feces of pre-clinical and clinical cervids by RT-QuIC, which can be a practical tool for non-invasive CWD diagnosis.

Here, we present a protocol to describe a simple, fast and efficient prion amplification technique, the real-time quaking-induced conversion (RT-QuIC) method.

In tempo reale tremare-indotta conversione analisi per rilevazione di CWD prioni nel materiale fecale

The RT-QuIC technique is a sensitive in vitro cell-free prion amplification assay based mainly on the seeded misfolding and aggregation of recombinant ...

Building Up a High-throughput Screening Platform to Assess the Heterogeneity of HER2 Gene Amplification in Breast Cancers

Targeted therapies against the human epidermal growth factor receptor 2 (HER2) have radically changed the outcome of patients with HER2-positive breast cancers. However, a minority of cases displays a heterogeneous distribution of HER2-positive cells, which generates major clinical challenges. To date, no reliable and standardized protocols for the characterization and quantification of HER2 heterogeneous gene amplification in large cohorts have been proposed. Here, we present a high-throughput methodology to simultaneously assess the HER2 status across different topographic areas of multiple breast cancers. In particular, we illustrate the laboratory procedure to construct enhanced tissue microarrays (TMAs) incorporating a targeted mapping of the tumors. All TMA parameters have been specifically optimized for the silver in situ hybridization (SISH) of formalin-fixed paraffin-embedded (FFPE) breast tissues. Immunohistochemical analysis of the prognostic and predictive biomarkers (i.e., ER, PR, Ki67, and HER2) should be performed using automated procedures. A customized SISH protocol has been implemented to allow a high-quality molecular analysis across multiple tissues that underwent different fixation, processing, and storage procedures. In this study, we provide a proof-of-principle that specific DNA sequences could be localized simultaneously in distinct topographic areas of multiple and heterogeneously processed breast cancers using an efficient and cost-effective method.

Heterogeneous distribution of HER2-positive cells can be observed in a subset of breast cancers and generates clinical dilemmas. Here, we introduce a reliable and cost-effective protocol to define, quantify, and compare HER2 intra-tumor genetic heterogeneity in a large series of heterogeneously processed breast cancers.

Costruire una piattaforma di High-throughput Screening per valutare l'eterogeneità dell'amplificazione del Gene HER2 nei cancri al seno

Targeted therapies against the human epidermal growth factor receptor 2 (HER2) have radically changed the outcome of patients with HER2-positive breast ...

Dissecting Multi-protein Signaling Complexes by Bimolecular Complementation Affinity Purification (BiCAP)

The assembly of protein complexes is a central mechanism underlying the regulation of many cell signaling pathways. A major focus of biomedical research is deciphering how these dynamic protein complexes act to integrate signals from multiple sources in order to direct a specific biological response, and how this becomes deregulated in many disease settings. Despite the importance of this key biochemical mechanism, there is a lack of experimental techniques that can facilitate the specific and sensitive deconvolution of these multi-molecular signaling complexes.
Here this shortcoming is addressed through the combination of a protein complementation assay with a conformation-specific nanobody, which we have termed Bimolecular Complementation Affinity Purification (BiCAP). This novel technique facilitates the specific isolation and downstream proteomic characterization of any pair of interacting proteins, to the exclusion of un-complexed individual proteins and complexes formed with competing binding partners. 
The BiCAP technique is adaptable to a wide array of downstream experimental assays, and the high degree of specificity afforded by this technique allows more nuanced investigations into the mechanics of protein complex assembly than is currently possible using standard affinity purification techniques.

Dissecting Multi-protein Signaling Complexes by Bimolecular Complementation Affinity Purification BiCAP

This manuscript describes the protocol for Bimolecular Complementation Affinity Purification (BiCAP). This novel method facilitates the specific isolation and downstream proteomic characterization of any two interacting proteins, while excluding un-complexed individual proteins as well as complexes formed with competing binding partners.

Dissezione multiproteici segnalazione di purificazione di affinità di complementazione bimolecolare (BiCAP)

The assembly of protein complexes is a central mechanism underlying the regulation of many cell signaling pathways. A major focus of biomedical research ...

Automated Behavioral Analysis of Large C. elegans Populations Using a Wide Field-of-view Tracking Platform

Caenorhabditis elegans is a well-established animal model in biomedical research, widely employed in functional genomics and ageing studies. To assess the health and fitness of the animals under study, one typically relies on motility readouts, such as the measurement of the number of body bends or the speed of movement. These measurements usually involve manual counting, making it challenging to obtain good statistical significance, as time and labor constraints often limit the number of animals in each experiment to 25 or less. Since high statistical power is necessary to obtain reproducible results and limit false positive and negative results when weak phenotypic effects are investigated, efforts have recently been made to develop automated protocols focused on increasing the sensitivity of motility detection and multi-parametric behavioral profiling. In order to extend the limit of detection to the level needed to capture the small phenotypic changes that are often crucial in genetic studies and drug discovery, we describe here a technological development that enables the study of up to 5,000 individual animals simultaneously, increasing the statistical power of the measurements by about 1,000-fold compared to manual assays and about 100-fold compared to other available automated methods.

Automated Behavioral Analysis of Large C. elegans Populations Using a Wide Field-of-view Tracking Platform

We describe protocols for using the wide field-of-view nematode tracking platform (WF-NTP), which enables high-throughput phenotypic characterization of large populations of Caenorhabditis elegans. These protocols can be used to characterize subtle behavioral changes in mutant strains or in response to pharmacological treatment in a highly scalable fashion.

Analisi del comportamento di grande c. elegans popolazioni utilizzando un ampio campo di vista Monitoraggio piattaforma automatizzata

Caenorhabditis elegans is a well-established animal model in biomedical research, widely employed in functional genomics and ageing studies. To assess the ...

Generation, Amplification, and Titration of Recombinant Respiratory Syncytial Viruses

The use of recombinant viruses has become crucial in basic or applied virology. Reverse genetics has been proven to be an extremely powerful technology, both to decipher viral replication mechanisms and to study antivirals or provide development platform for vaccines. The construction and manipulation of a reverse genetic system for a negative-strand RNA virus such as a respiratory syncytial virus (RSV), however, remains delicate and requires special know-how. The RSV genome is a single-strand, negative-sense RNA of about 15 kb that serves as a template for both viral RNA replication and transcription. Our reverse genetics system uses a cDNA copy of the human RSV long strain genome (HRSV). This cDNA, as well as cDNAs encoding viral proteins of the polymerase complex (L, P, N, and M2-1), are placed in individual expression vectors under T7 polymerase control sequences. The transfection of these elements in BSR-T7/5 cells, which stably express T7 polymerase, allows the cytoplasmic replication and transcription of the recombinant RSV, giving rise to genetically modified virions. A new RSV, which is present at the cell surface and in the culture supernatant of BSRT7/5, is gathered to infect human HEp-2 cells for viral amplification. Two or three rounds of amplification are needed to obtain viral stocks containing 1 x 106 to 1 x 107 plaque-forming units (PFU)/mL. Methods for the optimal harvesting, freezing, and titration of viral stocks are described here in detail. We illustrate the protocol presented here by creating two recombinant viruses respectively expressing free green fluorescent protein (GFP) (RSV-GFP) or viral M2-1 fused to GFP (RSV-M2-1-GFP). We show how to use RSV-GFP to quantify RSV replication and the RSV-M2-1-GFP to visualize viral structures, as well as viral protein dynamics in live cells, by using video microscopy techniques.

We describe a method for generating and amplifying genetically modified respiratory syncytial viruses (RSVs) and an optimized plaque assay for RSVs. We illustrate this protocol by creating two recombinant viruses that respectively allow quantification of RSV replication and live analysis of RSV inclusion bodies and inclusion bodies-associated granules dynamics.

Generazione, amplificazione e titolazione del virus sinciziale respiratorio ricombinante

The use of recombinant viruses has become crucial in basic or applied virology. Reverse genetics has been proven to be an extremely powerful technology, ...

Reverse Transcription Loop-Mediated Isothermal Amplification (RT-LAMP) Assay for the Specific and Rapid Detection of Tilapia Lake Virus

Tilapia lake virus disease (TiLVD), an emerging viral disease in tilapia caused by the tilapia lake virus (TiLV), is a persistent challenge in the aquaculture industry that has resulted in the mass morbidity and mortality of tilapia in many parts of the world. An effective, rapid, and accurate diagnostic assay for TiLV infection is therefore necessary to detect the initial infection and to prevent the spread of the disease in aquaculture farming. In this study, a highly sensitive and practical reverse transcription loop-mediated isothermal amplification (RT-LAMP) method is presented to detect tilapia lake virus in fish tissue. A comparison of the RT-qPCR and RT-LAMP assays of infected samples revealed positive results in 63 (100%) and 51 (80.95%) samples, respectively. Moreover, an analysis of uninfected samples showed that all 63 uninfected tissues yielded negative results for both the RT-qPCR and RT-LAMP assays. The cross-reactivity with five pathogens in tilapia was evaluated using RT-LAMP, and all the tests showed negative results. Both the liver and mucus samples obtained from infected fish showed comparable results using the RT-LAMP method, suggesting that mucus can be used in RT-LAMP as a nonlethal assay to avoid killing fish. In conclusion, the results demonstrated that the presented RT-LAMP assay provides an effective method for TiLV detection in tilapia tissue within 1 h. The method is therefore recommended as a screening tool on farms for the rapid diagnosis of TiLV.

Reverse Transcription Loop-Mediated Isothermal Amplification RT-LAMP Assay for the Specific and Rapid Detection of Tilapia Lake Virus

We present an RT-LAMP assay for the detection of TiLV in tilapia fish using simple instruments over a relatively short period of time compared to conventional RT-PCR techniques. This protocol may help control the epidemic spread of TiLVD, especially in developing countries.

Analisi dell'amplificazione isotermica mediata dal ciclo di trascrizione inversa (RT-LAMP) Per il rilevamento specifico e rapido del virus del lago Tilapia

Proteine ​​ciclica Amplificazione misfolding di prioni

Proteine ciclica Amplificazione misfolding di prioni