Vorremmo ringraziare la Fondazione canadese per l&#39;innovazione, la British Columbia Fondo di conoscenza per lo sviluppo e la Nazionale di Scienze e Ingegneria Research Council (NSERC) del Canada per sostenere gli studi in corso sulle regioni di scarsità di ossigeno delle acque costiere oceaniche e aperto. DAW è stata sostenuta da borse di studio da NSERC, Killam e la fondazione TULA Centro finanziato per la diversità microbica e Evolution.

<ol><li> Messa a punto di apparecchiature di filtrazione <ol><li> Per impostare l&#39;apparato di filtrazione, utilizzare una pinzetta per posizionare un grado GF / D filtro in unità abitativa prefiltro. Liberamente stringere la custodia a mano. Come regola generale, non stringere troppo o l&#39;unità perdite una volta che la parte di pompaggio. </li><li> Sostituire il tappo di damigiana con il tappo in autoclave e il tubo attaccato con attenzione inserito il tubo interno in damigiana senza toccarla. Se necessario, utilizzare una pinzetta per guidare il tubo nel damigiana. </li><li> Far passare il tubo esterno attraverso la pompa peristaltica. </li><li> Collegare unità abitative prefiltro alla fine di entrambi i tubi esterni (2 unità per damigiana). Stringere la connessione con le pinze. </li></ol></li><li> Filtrazione di acqua di mare <ol><li> Per iniziare a filtrare l&#39;acqua di mare, accendere la pompa e impostare la velocità di flusso a 1. Guarda per assicurare che l&#39;acqua viene pompata nella direzione corretta. </li><li> Lasciare 500 ml di acqua di fluire liberamente attraverso l&#39;unità prefiltro e in un contenitore 1 L. </li><li> Spegnere la pompa, e collegare un filtro Sterivex al raccordo maschio luer alla fine privo di configurazione prefiltro. Serrare le abitazioni prefiltro comodamente a mano. </li><li> Guarda per l&#39;alloggiamento prefiltro e al collegamento tra il corpo prefiltro e il tubo che porta alla damigiana. Se si verificano perdite, spegnere la pompa fuori e allentare e stringere di nuovo la custodia prefiltro di conseguenza. Accendere la pompa di nuovo. </li><li> Raccogliere il filtrato in 4 fiaschi L. Una volta che sono piene, vuote i flaconi in una damigiana pulito. Assicurarsi di prendere nota del volume passa attraverso ciascun filtro. Raccolti filtrato possono essere ulteriormente elaborati, come ad esempio la filtrazione di virus. </li><li> Continuare a filtrare l&#39;acqua fino a quando non viene lasciato in damigiane. Solita gamma di filtrazione volte tra 4-5 ore / 20 L damigiana, ma questo dipende drammaticamente dalla quantità di biomassa all&#39;interno dell&#39;acqua. </li><li> Una volta che la filtrazione è completa, accendere la pompa e staccare i filtri Sterivex. </li></ol></li><li> Conservazione dei filtri <ol><li> Per memorizzare i filtri, prima espellere l&#39;acqua residua con una siringa da 30-60 ml. </li><li> Usando una pipetta, aggiungere buffer di lisi 1.8ml al filtro, mantenendo ~ 200 ul di spazio nel filtro per la successiva aggiunta di reagenti. </li><li> Sigillare la parte inferiore e superiore del filtro Sterivex con un piccolo pezzo di Parafilm, i filtri e l&#39;etichetta con la data e l&#39;identificazione del campione. </li><li> Conservare i filtri in un pre-etichettati tubo da 50 ml di falco a -80 ° C </li><li> Rimuovere i filtri dalla unità abitativa e metterli in etichetta tubi Falcon da 50 ml contenente 2 ml di tampone di lisi. Conservare questi a -80 ° C. </li></ol></li><li> Pulizia <ol><li> Per la pulizia finale, posto il tubo che era dentro la damigiana in un pallone contenente 0,1 M HCl </li><li> Diretto il tubo che porta al pallone 4L in damigiana originale. </li><li> Accendere la pompa e correre a 3, raccogliendo il flusso attraverso eseguito in damigiana originale. </li><li> Infine, sciacquare il tubo con l&#39;acqua in autoclave. </li></ol></li></ol> Risultati rappresentante: Il risultato finale è costituito da due filtri Sterivix ognuno contenente biomassa microbica da circa 10 L di acqua di mare nella gamma di dimensioni di 0.22μm e 2.7μm. Questo è memorizzato in tampone di lisi e pronto per l&#39;estrazione del DNA. Inoltre, questa procedura raccoglie e concentra biomassa superiore a 2,7 micron, il GF / D prefiltri. Questo è anche memorizzate nel buffer di lisi e pronto per l&#39;estrazione del DNA. Se i passaggi ulteriori elaborazioni sono adottate, il 0,22 mM flow-through può essere concentrato verso il basso per raccogliere la frazione virale pure.

The authors have nothing to disclose.

E &#39;indispensabile per pulire panche e pompe con un panno umido dopo l&#39;uso per rimuovere ogni traccia persistente di acqua salata che altrimenti corrodere attrezzature. Anche se la procedura è semplice, il requisito di tempo può essere esteso a seconda della concentrazione di biomassa o detriti nel campione essere filtrato.

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Peristaltic pump</td>
<td>&nbsp;</td>
<td>Masterflex (Cole Palmer)</td>
<td>77913-20, 77200-62, 77200-04</td>
<td>&nbsp;</td>
<tr>
<td>Tygon LFL tubing</td>
<td>&nbsp;</td>
<td>Masterflex (Cole Palmer)</td>
<td>06429-24</td>
<td>For filtration apparatus</td>
</tr>
<tr>
<td>Hose clamps</td>
<td>&nbsp;</td>
<td>Cole Palmer</td>
<td>0683204</td>
<td>For filtration apparatus</td>
</tr>
<tr>
<td>1/4&#x201D; x 3/16&#x201D; pipe adaptors</td>
<td>&nbsp;</td>
<td>Cole Palmer</td>
<td>31702-20</td>
<td>For filtration apparatus</td>
</tr>
<tr>
<td>Polypropylene prefilter housing</td>
<td>&nbsp;</td>
<td>ADVANTEC</td>
<td>501200</td>
<td>For filtration apparatus</td>
</tr>
<tr>
<td>Metal luer fitting (Hose end to Male luer lock)</td>
<td>&nbsp;</td>
<td>Cole Palmer</td>
<td>31507-27</td>
<td>For filtration apparatus</td>
</tr>
<tr>
<td>2&#x201C; Magnets</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>For filtration apparatus</td>
<td>&nbsp;</td>
<tr>
<td>3 port carboy caps</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>For filtration apparatus</td>
</tr>
<tr>
<td>GV 0.22 &mu;m STERIVIX filters</td>
<td>&nbsp;</td>
<td>Millipore</td>
<td>SVGV01R5</td>
<td>&nbsp;</td>
<tr>
<td>47 mm diameter 2.7 &mu;m GF/D filters</td>
<td>&nbsp;</td>
<td>Whatman</td>
<td>1823047</td>
<td>&nbsp;</td>
<tr>
<td>Lysis buffer</td>
<td> Reagent</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>0.75 M sucrose, 40 mM EDTA, 50 mM Tris (pH 8.3)</td>
</tr>
<tr>
<td>0.1 % HCl</td>
<td>Reagent</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>For post-filtration rinse</td>
</tr>
<tr>
<td>Autoclaved water</td>
<td>Reagent</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>For post-filtration rinse</td>
</tr>		</tbody>
		</table>
		</div>

large volume (20l+) filtration of coastal seawater samples

Il flusso di lavoro inizia con la raccolta delle acque marine costiere per la comunità microbica a valle, le analisi dei nutrienti e dei gas traccia. Per questo metodo, i campioni sono stati raccolti dal ponte della HMS operativo John Strickland a Inlet Saanich. Questo volume video di documenti di grandi dimensioni (≥ 20 L) filtrazione di biomassa microbica, compresa tra 0.22μm e 2.7μm di diametro, dalla colonna d&#39;acqua. Due campioni 20L può essere filtrato contemporaneamente utilizzando una sola unità pompa dotata di quattro teste rotanti. La filtrazione è fatto nel settore lunghi viaggi, o immediatamente dopo il ritorno per gite di un giorno. E &#39;importante registrare la quantità di acqua che passa attraverso ogni unità sterivex filtro. Per prevenire la formazione di biofilm tra i viaggi di campionamento, tutte le apparecchiature di filtrazione devono essere lavate con acido cloridrico diluito e acqua deionizzata e sterilizzati in autoclave immediatamente dopo l&#39;uso. Questa procedura richiederà circa 5 ore più un ora in più per la pulizia.

Watch this Scientific Journal Video about Large Volume 20L+ Filtration of Coastal Seawater Samples at JoVE.com

Large Volume 20L+ Filtration of Coastal Seawater Samples

Questo volume video di documenti di grandi dimensioni (≥ 20 L) filtrazione di biomassa microbica, compresa tra 0.22μm e 2.7μm di diametro, dalla colonna d&#39;acqua.

Volume di grandi dimensioni (20L +) Filtrazione di campioni d&#39;acqua di mare costiero

The workflow begins with the collection of coastal marine waters for downstream microbial community, nutrient and trace gas analyses. For this method, ...

large-volume-20l-filtration-of-coastal-seawater-samples

Research

JoVE Journal

Biology

Large Volume (20L+) Filtration of Coastal Seawater Samples

11.7K Views.  University of British Columbia - UBC. Questo volume video di documenti di grandi dimensioni (≥ 20 L) filtrazione di biomassa microbica, compresa tra 0.22μm e 2.7μm di diametro, dalla colonna d'acqua.

Video: Large Volume 20L+ Filtration of Coastal Seawater Samples

Large-Scale Screens of Metagenomic Libraries

Metagenomic libraries archive large fragments of contiguous genomic sequences from microorganisms without requiring prior cultivation. Generating a streamlined procedure for creating and screening metagenomic libraries is therefore useful for efficient high-throughput investigations into the genetic and metabolic properties of uncultured microbial assemblages. Here, key protocols are presented on video, which we propose is the most useful format for accurately describing a long process that alternately depends on robotic instrumentation and (human) manual interventions. First, we employed robotics to spot library clones onto high-density macroarray membranes, each of which can contain duplicate colonies from twenty-four 384-well library plates. Automation is essential for this procedure not only for accuracy and speed, but also due to the miniaturization of scale required to fit the large number of library clones into highly dense spatial arrangements. Once generated, we next demonstrated how the macroarray membranes can be screened for genes of interest using modified versions of standard protocols for probe labeling, membrane hybridization, and signal detection. We complemented the visual demonstration of these procedures with detailed written descriptions of the steps involved and the materials required, all of which are available online alongside the video.

Su larga scala Schermi di librerie metagenomiche

Metagenomic libraries archive large fragments of contiguous genomic sequences from microorganisms without requiring prior cultivation.  Generating a ...

Ricerca

Biologia

Seawater Sampling and Collection

This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass concentration, nucleic acid purification, cell abundance, nutrient and trace gas analyses. For today's demonstration samples were collected from the deck of the HMS John Strickland operating in Saanich Inlet. An A-frame derrick, with a multi-purpose winch and cable system, is used in combination with Niskin or Go-Flo water sampling bottles. Conductivity, Temperature, and Depth (CTD) sensors are also used to sample the underlying water mass. To minimize outgassing, trace gas samples are collected first.  Then, nutrients, water chemistry, and cell counts are determined. Finally, waters are collected for biomass filtration. The set-up and collection time for a single cast is ~1.5 hours at a maximum depth of 215 meters. Therefore, a total of 6 hours is generally needed to complete the collection series described here.

This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass concentration, nucleic acid purification, cell abundance, nutrient and trace gas analyses.

Campionamento di acqua di mare e di raccolta

This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass ...

Small Volume (1-3L) Filtration of Coastal Seawater Samples

The workflow begins with the collection of coastal marine waters for downstream microbial community, nutrient and trace gas analyses. For today s demonstration samples were collected from the deck of the HMS John Strickland operating in Saanich Inlet. This video documents small volume (~1 L) filtration of microbial biomass from the water column. The protocol is an extension of the large volume sampling protocol described earlier, with one major difference: here, there is no pre-filtration step, so all size classes of biomass are collected down to the 0.22 &mu;m filter cut-off. Samples collected this way are ideal for nucleic acid analysis. The set-up, filtration, and clean-up steps each take about 20-30 minutes. If using two peristaltic pumps simultaneously, up to 8 samples may be filtered at the same time. To prevent biofilm formation between sampling trips, all filtration equipment must be rinsed with dilute HCl and deionized water and autoclaved immediately after use.

Small Volume 1-3L Filtration of Coastal Seawater Samples

This video documents small volume (~1 L) filtration of microbial biomass from the water column.

Volume piccoli (1-3L) Filtrazione di campioni d&#39;acqua di mare costiero

The workflow begins with the collection of coastal marine waters for downstream microbial community, nutrient and trace gas analyses. For today s ...

Large Insert Environmental Genomic Library Production

The vast majority of microbes in nature currently remain inaccessible to traditional cultivation methods. Over the past decade, culture-independent environmental genomic (i.e. metagenomic) approaches have emerged, enabling researchers to bridge this cultivation gap by capturing the genetic content of indigenous microbial communities directly from the environment. To this end, genomic DNA libraries are constructed using standard albeit artful laboratory cloning techniques. Here we describe the construction of a large insert environmental genomic fosmid library with DNA derived from the vertical depth continuum of a seasonally hypoxic fjord. This protocol is directly linked to a series of connected protocols including coastal marine water sampling [1], large volume filtration of microbial biomass [2] and a DNA extraction and purification protocol [3]. At the outset, high quality genomic DNA is end-repaired with the creation of 5 -phosphorylated blunt ends. End-repaired DNA is subjected to pulsed-field gel electrophoresis (PFGE) for size selection and gel extraction is performed to recover DNA fragments between 30 and 60 thousand base pairs (Kb) in length. Size selected DNA is purified away from the PFGE gel matrix and ligated to the phosphatase-treated blunt-end fosmid CopyControl vector pCC1 (EPICENTRE <a href="http://www.epibio.com/item.asp?ID=385">http://www.epibio.com/item.asp?ID=385</a>). Linear concatemers of pCC1 and insert DNA are subsequently headfull packaged into phage particles by lambda terminase, with subsequent infection of phage-resistant E. coli cells. Successfully transduced clones are recovered on LB agar plates under antibiotic selection and archived in 384-well plate format using an automated colony picking robot (Qpix2, GENETIX). The current protocol draws from various sources including the CopyControl Fosmid Library Production Kit from EPICENTRE and the published works of multiple research groups [4-7]. Each step is presented with best practice in mind. Whenever possible we highlight subtleties in execution to improve overall quality and efficiency of library production. The whole process of fosmid library production and automated colony picking takes at least 7-10 days as there are many incubation steps included. However, there are several stopping points possible which are mentioned within the protocol.

Construction of a fosmid library with environmental genomic DNA isolated from the vertical depth continuum of a seasonally hypoxic fjord is described. The resulting clone library is picked into 384-well plates and archived for downstream sequencing and functional screening by the application of an automated colony picking system.

Inserire grande Ambientale Genomic Produzione Biblioteca

The vast majority of microbes in nature currently remain inaccessible to traditional cultivation methods. Over the past decade, culture-independent ...

Absolute Quantum Yield Measurement of Powder Samples

Measurement of fluorescence quantum yield has become an important tool in the search for new solutions in the development, evaluation, quality control and research of illumination, AV equipment, organic EL material, films, filters and fluorescent probes for bio-industry.
Quantum yield is calculated as the ratio of the number of photons absorbed, to the number of photons emitted by a material. The higher the quantum yield, the better the efficiency of the fluorescent material.
For the measurements featured in this video, we will use the Hitachi F-7000 fluorescence spectrophotometer equipped with the Quantum Yield measuring accessory and Report Generator program. All the information provided applies to this system. 
Measurement of quantum yield in powder samples is performed following these steps:
<ol>
 <li>Generation of instrument correction factors for the excitation and emission monochromators. This is an important requirement for the correct measurement of quantum yield. It has been performed in advance for the full measurement range of the instrument and will not be shown in this video due to time limitations.</li>
 <li>Measurement of integrating sphere correction factors. The purpose of this step is to take into consideration reflectivity characteristics of the integrating sphere used for the measurements.</li>
 <li>Reference and Sample measurement using direct excitation and indirect excitation.</li>
 <li>Quantum Yield calculation using Direct and Indirect excitation. Direct excitation is when the sample is facing directly the excitation beam, which would be the normal measurement setup. However, because we use an integrating sphere, a portion of the emitted photons resulting from the sample fluorescence are reflected by the integrating sphere and will re-excite the sample, so we need to take into consideration indirect excitation. This is accomplished by measuring the sample placed in the port facing the emission monochromator, calculating indirect quantum yield and correcting the direct quantum yield calculation.</li>
 <li>Corrected quantum yield calculation.</li>
 <li>Chromaticity coordinates calculation using Report Generator program.</li>
</ol>
The Hitachi F-7000 Quantum Yield Measurement System offer advantages for this
application, as follows:
<ul>
 <li>High sensitivity (S/N ratio 800 or better RMS). Signal is the Raman band of water measured under the following conditions: Ex wavelength 350 nm, band pass Ex and Em 5 nm, response 2 sec), noise is measured at the maximum of the Raman peak. High sensitivity allows measurement of samples even with low quantum yield. Using this system we have measured quantum yields as low as 0.1 for a sample of salicylic acid and as high as 0.8 for a sample of magnesium tungstate.</li>
 <li>Highly accurate measurement with a dynamic range of 6 orders of magnitude allows for measurements of both sharp scattering peaks with high intensity, as well as broad fluorescence peaks of low intensity under the same conditions. </li>
 <li>High measuring throughput and reduced light exposure to the sample, due to a high scanning speed of up to 60,000 nm/minute and automatic shutter function. </li>
 <li>Measurement of quantum yield over a wide wavelength range from 240 to 800 nm.</li>
 <li>Accurate quantum yield measurements are the result of collecting instrument spectral response and integrating sphere correction factors before measuring the sample.</li>
 <li>Large selection of calculated parameters provided by dedicated and easy to use software.
</li>
</ul> 
During this video we will measure sodium salicylate in powder form which is known to have a quantum yield value of 0.4 to 0.5.

In this video we will demonstrate measuring and calculating absolute quantum yield and chromaticity coordinates directly in powder samples using the Hitachi F-7000 Quantum Yield Measuring System.

Absolute Quantum la misurazione del rendimento dei campioni di polvere

Measurement of fluorescence quantum yield has become an important tool in the search for new solutions in the development, evaluation, quality control and ...

Measuring Peptide Translocation into Large Unilamellar Vesicles

There is an active interest in peptides that readily cross cell membranes without the assistance of cell membrane receptors1. Many of these are referred to as cell-penetrating peptides, which are frequently noted for their potential as drug delivery vectors1-3. Moreover, there is increasing interest in antimicrobial peptides that operate via non-membrane lytic mechanisms4,5, particularly those that cross bacterial membranes without causing cell lysis and kill cells by interfering with intracellular processes6,7. In fact, authors have increasingly pointed out the relationship between cell-penetrating and antimicrobial peptides1,8. A firm understanding of the process of membrane translocation and the relationship between peptide structure and its ability to translocate requires effective, reproducible assays for translocation. Several groups have proposed methods to measure translocation into large unilamellar lipid vesicles (LUVs)9-13. LUVs serve as useful models for bacterial and eukaryotic cell membranes and are frequently used in peptide fluorescent studies14,15. Here, we describe our application of the method first developed by Matsuzaki and co-workers to consider antimicrobial peptides, such as magainin and buforin II16,17. In addition to providing our protocol for this method, we also present a straightforward approach to data analysis that quantifies translocation ability using this assay. The advantages of this translocation assay compared to others are that it has the potential to provide information about the rate of membrane translocation and does not require the addition of a fluorescent label, which can alter peptide properties18, to tryptophan-containing peptides. Briefly, translocation ability into lipid vesicles is measured as a function of the Foster Resonance Energy Transfer (FRET) between native tryptophan residues and dansyl phosphatidylethanolamine when proteins are associated with the external LUV membrane (Figure 1). Cell-penetrating peptides are cleaved as they encounter uninhibited trypsin encapsulated with the LUVs, leading to disassociation from the LUV membrane and a drop in FRET signal. The drop in FRET signal observed for a translocating peptide is significantly greater than that observed for the same peptide when the LUVs contain both trypsin and trypsin inhibitor, or when a peptide that does not spontaneously cross lipid membranes is exposed to trypsin-containing LUVs. This change in fluorescence provides a direct quantification of peptide translocation over time.

This protocol details a method for the quantitative measure of peptide translocation into large unilamellar lipid vesicles. This method also provides information about the rate of membrane translocation and can be used to identify peptides that efficiently and spontaneously cross lipid bilayers.

Misurazione Traslocazione Peptide in grandi vescicole unilamellari

There is an active interest in peptides that readily cross cell membranes without the assistance of cell membrane receptors1.  Many of these are referred ...

A High-throughput Method for Measurement of Glomerular Filtration Rate in Conscious Mice

The measurement of glomerular filtration rate (GFR) is the gold standard in kidney function assessment. Currently, investigators determine GFR by measuring the level of the endogenous biomarker creatinine or exogenously applied radioactive labeled inulin (3H or 14C). Creatinine has the substantial drawback that proximal tubular secretion accounts for ~50% of total renal creatinine excretion and therefore creatinine is not a reliable GFR marker. Depending on the experiment performed, inulin clearance can be determined by an intravenous single bolus injection or continuous infusion (intravenous or osmotic minipump). Both approaches require the collection of plasma or plasma and urine, respectively. Other drawbacks of radioactive labeled inulin include usage of isotopes, time consuming surgical preparation of the animals, and the requirement of a terminal experiment. Here we describe a method which uses a single bolus injection of fluorescein isothiocyanate-(FITC) labeled inulin and the measurement of its fluorescence in 1-2 &mu;l of diluted plasma. By applying a two-compartment model, with 8 blood collections per mouse, it is possible to measure GFR in up to 24 mice per day using a special work-flow protocol. This method only requires brief isoflurane anesthesia with all the blood samples being collected in a non-restrained and awake mouse. Another advantage is that it is possible to follow mice over a period of several months and treatments (i.e. doing paired experiments with dietary changes or drug applications). We hope that this technique of measuring GFR is useful to other investigators studying mouse kidney function and will replace less accurate methods of estimating kidney function, such as plasma creatinine and blood urea nitrogen.

Measurement of glomerular filtration rate (GFR) is the gold standard for kidney function assessment. Here we describe a high-throughput method which allows the determination of GFR in conscious mice by using a single bolus injection, determination of fluorescein isothiocyanate (FITC)-inulin in plasma and calculation of GFR by a two-phase exponential decay model.

Un metodo ad alta velocità per la misura della velocità di filtrazione glomerulare in topi coscienti

The measurement of  glomerular filtration rate (GFR) is the gold standard in kidney function  assessment. Currently, investigators determine GFR by ...

Rapid Isolation And Purification Of Mitochondria For Transplantation By Tissue Dissociation And Differential Filtration

Previously described mitochondrial isolation methods using differential centrifugation and/or Ficoll gradient centrifugation require 60 to 100 min to complete. We describe a method for the rapid isolation of mitochondria from mammalian biopsies using a commercial tissue dissociator and differential filtration. In this protocol, manual homogenization is replaced with the tissue dissociator&#8217;s standardized homogenization cycle. This allows for uniform and consistent homogenization of tissue that is not easily achieved with manual homogenization. Following tissue dissociation, the homogenate is filtered through nylon mesh filters, which eliminate repetitive centrifugation steps. As a result, mitochondrial isolation can be performed in less than 30 min. This isolation protocol yields approximately 2 x 1010 viable and respiration competent mitochondria from 0.18 &#177; 0.04 g (wet weight) tissue sample.

A method for rapid isolation of mitochondria from mammalian tissue biopsies is described. Rat liver or skeletal muscle preparations were homogenized with a commercial tissue dissociator and mitochondria were isolated by differential filtration through nylon mesh filters. Mitochondrial isolation time is &#60;30 min compared to 60 - 100 min using alternative methods.

Isolamento rapida e purificazione di mitocondri per il trapianto da tessuto Dissociazione e Filtrazione Differenziale

Previously described mitochondrial isolation methods using differential centrifugation and/or Ficoll gradient centrifugation require 60 to 100 min to ...

Physiology Lab Demonstration: Glomerular Filtration Rate in a Rat

Measurements of glomerular filtration rate (GFR), and the fractional excretion of sodium (Na) and potassium (K) are critical in assessing renal function in health and disease. GFR is measured as the steady state renal clearance of inulin which is filtered at the glomerulus, but not secreted or reabsorbed along the nephron. The fractional excretion of Na and K can be determined from the concentration of Na and K in plasma and urine. The renal clearance of inulin can be demonstrated in an anesthetized animal which has catheters in the femoral artery, femoral vein and bladder. The equipment and supplies used for this procedure are those commonly available in a research core facility, and thus makes this procedure a practical means for measuring renal function. The purpose of this video is to demonstrate the procedures required to perform a lab demonstration in which renal function is assessed before and after a diuretic drug. The presented technique can be utilized to assess renal function in rat models of renal disease.

The purpose of this protocol is to demonstrate the principles and techniques for measuring and calculating glomerular filtration rate, urine flow rate, and excretion of sodium and potassium in a rat. This demonstration can be used to provide students with an overall conceptual understanding of how to measure renal function.

Fisiologia Lab Dimostrazione: filtrazione glomerulare in un ratto

Measurements of glomerular filtration rate (GFR), and the fractional excretion of sodium (Na) and potassium (K) are critical in assessing renal function ...

Measuring Pressure Volume Loops in the Mouse

Understanding the causes and progression of heart disease presents a significant challenge to the biomedical community. The genetic flexibility of the mouse provides great potential to explore cardiac function at the molecular level. The mouse&#39;s small size does present some challenges in regards to performing detailed cardiac phenotyping. Miniaturization and other advancements in technology have made many methods of cardiac assessment possible in the mouse. Of these, the simultaneous collection of pressure and volume data provides a detailed picture of cardiac function that is not available through any other modality. Here a detailed procedure for the collection of pressure-volume loop data is described. Included is a discussion of the principles underlying the measurements and the potential sources of error. Anesthetic management and surgical approaches are discussed in great detail as they are both critical to obtaining high quality hemodynamic measurements. The principles of hemodynamic protocol development and relevant aspects of data analysis are also addressed.

This manuscript describes a detailed protocol for the collection of pressure-volume data from the mouse.

Misurazione Loops Volume Pressione nel mouse

Understanding the causes and progression of heart disease presents a significant challenge to the biomedical community. The genetic flexibility of the ...