1. Preparación de la muestra El primer paso en el Western Blot es la preparación de muestras. Para preparar las muestras para el funcionamiento de un gel de células y tejidos deben ser zadas para liberar las proteínas de interés. <ul><li> Un práctico, listo para el uso de reactivos que es versátil y fácil de usar para la extracción de proteína soluble es CytoBuster o PhosphoSafe. Estos topes de extracción contienen detergentes optimizó para la extracción eficaz de las proteínas solubles de las células de mamíferos e insectos. La suave y no iónicos composición del Reactivo CytoBuster extracción de la proteína permite el aislamiento de la endógena funcionalmente activas o proteínas que se expresan sin necesidad de tratamiento secundario, tales como ultrasonidos o de congelación / descongelación. PhoshoSafe tiene el beneficio añadido de que contiene cuatro inhibidores de la fosfatasa. <ol><li> Precipitar las células por centrifugación a baja velocidad (por ejemplo, 5 minutos a 2500 xg), drenar el sedimento celular también. </li><li> Resuspender las células en el reactivo CytoBuster extracción de proteínas utilizando 150 l por cada 10 6 células (cantidad óptima de reactivo CytoBuster extracción de la proteína puede variar según el tamaño de la celda). </li><li> Incubar a temperatura ambiente durante 5 min. </li><li> Transferir a un tubo adecuado y vuelta durante 5 minutos a 16.000 xga 4 ° C. </li><li> Transferencia despejado sobrenadante (extracto de células) a un tubo nuevo y proceder a su análisis. </li></ol></li><li> Para la extracción de proteínas especializadas, se recomienda utilizar nuestros productos de alta calidad Kits ProteoExtract. EMD tiene más de una docena de kits para el aislamiento de las mitocondrias, la extracción de proteoma subcelular, la extracción de la proteína transmembrana, y muchos otros. Por favor, visite nuestra página de Western blot de aterrizaje para más detalles. </li><li> EMD también vende una amplia variedad de juegos de la proteasa y fosfatasa inhibidor de cóctel. Tan pronto como se produce la lisis, la proteolisis, desfosforilación y la desnaturalización de comenzar. Estos eventos se puede ralentizar enormemente si las muestras se mantienen en hielo oa 4 ° C en todo momento y los inhibidores adecuados se agregan a la nueva solución amortiguadora de lisis. Por favor, visite nuestra página de Western blot de aterrizaje para más detalles. </li></ul> 2. SDS-PAGE El segundo paso en el Western Blot es la separación de proteínas. Las proteínas se separan en función del peso molecular. <ul><li> Usted puede hacer su gel propia página, sin embargo, va a utilizar un comercial prefabricado gel. <ol><li> Después de preparar la muestra, usted está listo para determinar la concentración de proteínas. EMD tiene dos juegos para esta medición de la concentración, uno es el kit de proteínas sin interferencia de ensayo y el otro es el BCA Protein Kit de ensayo. </li><li> Una vez que la concentración de proteína se determina que estamos listos para preparar la muestra para la carga del gel. Los anticuerpos suelen reconocer una pequeña porción de la proteína de interés (en adelante, el epítopo) y este dominio pueden residir dentro de la conformación 3D de la proteína. Para habilitar el acceso de los anticuerpos a esta parte es necesario para desplegar la proteína. </li><li> Para desnaturalizar, use un tampón de carga con los aniónicos sulfato de sodio dodecil detergente desnaturalizante (SDS), y hervir la mezcla a 95-100 º C durante 5 minutos. Un tampón de carga fácil y cómodo de usar es la muestra de amortiguación 4X. </li></ol></li><li> Cargue el primer carril del pozo con marcador de proteína Trail Mix. Este marcador tiene tres bandas de referencia que le permiten controlar la electroforesis. Cuando el gel se tiñe, 10 bandas son visibles que van desde 10 hasta 225 kDa. </li><li> Llene la unidad de electroforesis con el correr de amortiguación. Por PAGE, esto es por lo general 1X Tris-glicina. Para recetas de amortiguación más detallada, visite la página de Western Blot. EMD ofrece una alta calidad de los reactivos tampones con nuestra línea de productos químicos OmniPur. Correr el gel a 220V durante 1 hora. </li><li> Una vez que las proteínas se han separado, tinción del gel con azul de Coomassie para asegurar que las proteínas han emigrado de manera uniforme y uniformemente. RAPIDstain es una mancha de ultra-sensible, que está listo para usar. No es necesario decolorar. </li></ul> 3. La proteína de transferencia Al igual que las proteínas con una carga eléctrica puede ser inducida a viajar a través de un gel en un campo eléctrico, por lo que las proteínas pueden ser transferidos de un campo eléctrico a partir del gel a una membrana, ya sean PVDF o nitrocelulosa. <ul><li> Hoy vamos a hacer una transferencia de humedad. En la transferencia de humedad, el gel y la membrana se intercala entre la esponja y papel (esponja / papel / gel / membrana / papel / esponja) y todos están apretados juntos después de que garantiza que no se han formado burbujas de aire entre el gel y la membrana. El sándwich se sumerge en tampón de transferencia al que se aplica un campo eléctrico. Las proteínas con carga negativa de viaje hacia el electrodo con carga positiva, pero la membrana se lo impide, se une a ellos, y les impide continuar. </li><li> Dos tipos de membranas disponibles: nitrocelulosa y PVDF. Ambos trabajan bien. Hoy vamos a estar utilizando PVDF. Membranas de PVDF requieren remojo en methanol durante unos minutos, seguida de transferencia de buffer fría durante 5 minutos. El gel también tiene que equilibrar durante unos minutos en tampón de transferencia helada. No hacerlo puede reducir el tamaño del gel durante la transferencia. </li><li> El buffer para la transferencia de humedad es 1X Tris-glicina con un 20% de metanol. Preparación detallada de búfer están disponibles en nuestro sitio web. </li><li> Una vez que se complete la transferencia, es una buena idea para visualizar las proteínas para asegurar una transferencia sin bolsas de aire. Esto se puede hacer fácilmente con RedAlert Western Blot manchas. Esta mancha está listo para su uso y la decoloración se puede hacer fácilmente con agua. </li></ul> 4. Anticuerpos y reactivos de accesorios <ul><li> El primer paso para hacer de sondeo y de anticuerpos contra el antígeno es bloquear la membrana. El bloqueo de la membrana impide la unión no específica de fondo. </li><li> Ya sea de leche sin grasa o BSA se puede utilizar como una solución de bloqueo. Sin embargo, cuando se utiliza fosfato anticuerpos específicos, no se recomienda el uso de la leche, ya que será causa de fondo de alta. </li><li> EMD ofrece varios reactivos de alta calidad de bloqueo, incluyendo SeaBlock, que es un agente de animales no mamíferos bloqueo y QuickBlocker BLOT, que es preparado, listo para usar agente de bloqueo. También contamos con alta calidad de BSA (fracción V) disponibles. <ol><li> Incubar la membrana de 1 hora a temperatura ambiente bajo agitación suave. </li><li> Lavar tres veces en PBST TBST o después de la incubación. Una manera fácil y conveniente de hacer TBST o PBST es utilizar nuestro tabletas (comprimidos PBS Tween / tabletas ENTRE TBS) </li></ol></li><li> Una vez que la membrana ha sido bloqueado, usted está listo para la incubación con el anticuerpo primario. EMD ha estado ofreciendo una amplia cartera de anticuerpos excepcional con la mejor garantía de anticuerpos en la industria por más de 30 años. Recuerde que con todos los anticuerpos EMD, ofrecemos un 100% sin riesgo de garantía. Compra de un anticuerpo y lo utilizan para cualquier especificidad de especie o de la aplicación que desee. Si el anticuerpo no funciona a su satisfacción, le daremos un crédito completo para ser utilizado en cualquier otro producto. Para más detalles, por favor visite nuestra página de Western blot web. <ol><li> Hoy vamos a estar incubando el anticuerpo primario utilizando nuestra solución al 1 de SignalBoost. SignalBoost es un gran producto que permite la señal para ser mejorada de manera significativa. Simplemente incubar su anticuerpo primario en la Solución 1 y se incuba durante 1 hora o como lo haría normalmente. No hay necesidad de agregar más agentes de bloqueo. Alternativamente, puede utilizar BSA o leche descremada en polvo como un agente de bloqueo. </li><li> Lavar con TBST. Hacemos TBST utilizando la lista a disolver la tableta TBST. </li><li> Incubar el anticuerpo secundario utilizando la solución de dos de SignalBoost. Incubar con el anticuerpo secundario en tampón de bloqueo durante 1 hora. Lavar la membrana de nuevo varias veces con TBST. </li></ol></li></ul> 5. Detección HRP para conjugar anticuerpos secundarios, ECL se utiliza tradicionalmente. Un reactivo ECL excelente que ofrecemos es RapidStep. Las ventajas de RapidStep es que no hay mezcla de luminal o potenciador es necesario. Simplemente rocíe la membrana de un par de veces y desarrollar el uso de las placas radiográficas. RapidStep ofrece una sensibilidad pictograma baja, así como emisores de luz de hasta 2 horas después de la adición del substrato.

<ol>
	<li>Towbin, H., Staehelin, T., Gordon, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophoretic+transfer+of+proteins+from+polyacrylamide+gels+to+nitrocellulose+sheets:+procedure+and+some+applications.">Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications.</a> Proc Natl Acad Sci U S A. 76 (9), 4350-4354 (1979).</li><li>Renart, J., Reiser, J., Stark, G. R., R, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transfer+of+proteins+from+gels+to+diazobenzyloxymethyl-paper+and+detection+with+antisera:+a+method+for+studying+antibody+specificity+and+antigen+structure.">Transfer of proteins from gels to diazobenzyloxymethyl-paper and detection with antisera: a method for studying antibody specificity and antigen structure.</a> Proc Natl Acad Sci U S A. 76 (7), 3116-3120 (1979).</li><li>Burnette, W. N. '. W. e. s. t. e. r. n. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=blotting':+electrophoretic+transfer+of+proteins+from+sodium+dodecyl+sulfate+polyacrylamide+gels+to+unmodified+nitrocellulose+and+radiographic+detection+with+antibody+and+radioiodinated+protein+A.">blotting': electrophoretic transfer of proteins from sodium dodecyl sulfate polyacrylamide gels to unmodified nitrocellulose and radiographic detection with antibody and radioiodinated protein A.</a> Analytical Biochemistry. 112, 195-203 (1981).</li><li>Ambroz, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improving+quantification+accuracy+for+Western+blots+Image+Analysis.">Improving quantification accuracy for Western blots Image Analysis.</a> , (2006).</li><li>Quan, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reactive+oxygen+species-mediated+endoplasmic+reticulum+stress+and+mitochondrial+dysfunction+contribute+to+cirsimartitin-induced+apoptosis+in+human+gallbladder+carcinoma+GBC-SD+cells.">Reactive oxygen species-mediated endoplasmic reticulum stress and mitochondrial dysfunction contribute to cirsimartitin-induced apoptosis in human gallbladder carcinoma GBC-SD cells.</a> Cancer Lett Article. , (2010).</li><li>O'Malley, D. e. r. v. i. a. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alterations+in+colonic+corticotrophin-releasing+factor+receptors+in+the+maternally+separated+rat+model+of+irritable+bowel+syndrome:+Differential+effects+of+acute+psychological+and+physical+stressors.">Alterations in colonic corticotrophin-releasing factor receptors in the maternally separated rat model of irritable bowel syndrome: Differential effects of acute psychological and physical stressors.</a> Peptides. 31 (4), 662-670 (2010).</li></ol>

Los autores Anna Eslami y Luján Jesse son empleados por EMD Chemicals Inc, que produce los reactivos y los instrumentos utilizados en el presente artículo.

En este vídeo de presentación, hemos destacado los pasos más importantes en Western Blot, que son la preparación de muestras, SDS-PAGE, la membrana de bloqueo / sondeo con anticuerpos, y la detección. Para cada paso del proceso, los protocolos adecuados y reactivos adecuados se deben utilizar para lograr resultados de alta calidad.

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		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>CytoBuster&trade; Protein Extraction Reagent</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>71009</td>
<td><a href="http://www.emdbiosciences.com/cytobuster">www.emdbiosciences.com/cytobuster</a> <a href="http://www.merck4biosciences.com/cytobuster">www.merck4biosciences.com/cytobuster</a></td>
</tr>
<tr>
<td>PhosphoSafe&trade; Extraction Reagent</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>71296</td>
<td><a href="http://www.emdbiosciences.com/phosphosafe">www.emdbiosciences.com/phosphosafe</a> <a href="http://www.merck4biosciences.com/phosphosafe">www.merck4biosciences.com/phosphosafe</a></td>
</tr>
<tr>
<td>Non-Interfering Protein Assay&trade; Kit</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>488250</td>
<td><a href="http://www.emdbiosciences.com/noninterfering">www.emdbiosciences.com/noninterfering</a> <a href="http://www.merck4biosciences.com/noninterfering">www.merck4biosciences.com/noninterfering</a></td>
</tr>
<tr>
<td>BCA Protein Assay Kit </td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>71285</td>
<td><a href="http://www.emdbiosciences.com/BCA">www.emdbiosciences.com/BCA</a> <a href="http://www.merck4biosciences.com/BCA">www.merck4biosciences.com/BCA</a></td>
</tr>
<tr>
<td>4X SDS Sample Buffer </td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>70607</td>
<td><a href="http://www.emdbiosciences.com/4XSDS">www.emdbiosciences.com/4XSDS</a> <a href="http://www.merck4biosciences.com/4XSDS">www.merck4biosciences.com/4XSDS</a></td>
</tr>
<tr>
<td>Trail Mix&trade; Protein Markers</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>70980</td>
<td><a href="http://www.emdbiosciences.com/trailmix">www.emdbiosciences.com/trailmix</a> <a href="http://www.merck4biosciences.com/trailmix">www.merck4biosciences.com/trailmix</a></td>
</tr>
<tr>
<td>ProteoExtract&trade; Protein Extraction Kits</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>&nbsp;</td>
<td><a href="http://www.emdbiosciences.com/proteoextract">www.emdbiosciences.com/proteoextract</a> <a href="http://www.merck4biosciences.com/proteoextract">www.merck4biosciences.com/proteoextract</a></td>
</tr>
<tr>
<td>OmniPur&reg; Products</td>
<td>&nbsp;</td>
<td>EMD Chemicals</td>
<td>&nbsp;</td>
<td><a href="http://www.emdbiosciences.com/omnipur">www.emdbiosciences.com/omnipur</a></td>
</tr>
<tr>
<td>RAPIDstain&trade; Reagent</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>553215</td>
<td><a href="http://www.emdbiosciences.com/rapidstain">www.emdbiosciences.com/rapidstain</a> <a href="http://www.merck4biosciences.com/rapidstain">www.merck4biosciences.com/rapidstain</a></td>
</tr>
<tr>
<td>RedAlert&trade; 10X Western Blot Stain</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>71078</td>
<td><a href="http://www.emdbiosciences.com/redalert">www.emdbiosciences.com/redalert</a> <a href="http://www.merck4biosciences.com/redalert">www.merck4biosciences.com/redalert</a></td>
</tr>
<tr>
<td>SeaBlock&trade; Reagent, Salmon Plasma</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>558300</td>
<td><a href="http://www.emdbiosciences.com/seablock">www.emdbiosciences.com/seablock</a> <a href="http://www.merck4biosciences.com/seablock">www.merck4biosciences.com/seablock</a></td>
</tr>
<tr>
<td>BLOT-QuickBlocker Reagent</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>WB57</td>
<td><a href="http://www.emdbiosciences.com/quickblocker">www.emdbiosciences.com/quickblocker</a> <a href="http://www.merck4biosciences.com/quickblocker">www.merck4biosciences.com/quickblocker</a></td>
</tr>
<tr>
<td>Albumin, Bovine Serum, Fraction V</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>12660</td>
<td><a href="http://www.emdbiosciences.com/bovineserum">www.emdbiosciences.com/bovineserum</a> <a href="http://www.merck4biosciences.com/bovineserum">www.merck4biosciences.com/bovineserum</a></td>
</tr>
<tr>
<td>PBS-TWEEN&reg; Tablets</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>524653</td>
<td><a href="http://www.emdbiosciences.com/PBST">www.emdbiosciences.com/PBST</a> <a href="http://www.merck4biosciences.com/PBST">www.merck4biosciences.com/PBST</a></td>
</tr>
<tr>
<td>TBS-TWEEN&reg; Tablets</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>524753</td>
<td><a href="http://www.emdbiosciences.com/TBST">www.emdbiosciences.com/TBST</a> <a href="http://www.merck4biosciences.com/TBST">www.merck4biosciences.com/TBST</a></td>
</tr>
<tr>
<td>SignalBoost&trade; Immunoreaction Enhancer Kit</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>407207</td>
<td><a href="http://www.emdbiosciences.com/signalboost">www.emdbiosciences.com/signalboost</a> <a href="http://www.merck4biosciences.com/signalboost">www.merck4biosciences.com/signalboost</a></td>
</tr>
<tr>
<td>RapidStep&trade; ECL Reagent</td>
<td>&nbsp;</td>
<td>EMD Chemicals/Merck KGaA</td>
<td>345818</td>
<td><a href="http://www.emdbiosciences.com/rapidstep">www.emdbiosciences.com/rapidstep</a> <a href="http://www.merck4biosciences.com/rapidstep">www.merck4biosciences.com/rapidstep</a></td>
</tr>		</tbody>
		</table>
		</div>

western blotting: sample preparation to detection

Western Blot es una técnica analítica para detectar proteínas específicas en una determinada muestra de tejido homogeneizado o extracto. Se utiliza la electroforesis en gel para separar las proteínas nativas o desnaturalizadas por la longitud del polipéptido (condiciones desnaturalizantes) o por la estructura 3-D de la proteína (nativo / condiciones no desnaturalizantes). Las proteínas se transfieren a una membrana (por lo general de nitrocelulosa o PVDF), donde se sondean (detectado), utilizando anticuerpos específicos para la proteína diana.

Watch this Scientific Journal Video about Western Blotting: Sample Preparation to Detection at JoVE.com

Western Blotting: Sample Preparation to Detection

Western Blot es una técnica analítica para detectar proteínas específicas en una determinada muestra de tejido homogeneizado o extracto.

Western Blot: Preparación de muestras para la detección

Western blotting is an analytical technique used to detect specific proteins in a given sample of tissue homogenate or extract. It uses gel ...

western-blotting-sample-preparation-to-detection

Research

JoVE Journal

Biology

138.9K vistas.  EMD Chemicals Inc.. Western Blot es una técnica analítica para detectar proteínas específicas en una determinada muestra de tejido homogeneizado o extracto.

Video: Western Blotting: Sample Preparation to Detection

MALDI Sample Preparation: the Ultra Thin Layer Method

This video demonstrates the preparation of an ultra-thin matrix/analyte layer for analyzing peptides and proteins by Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS) 1,2. The ultra-thin layer method involves the production of a substrate layer of matrix crystals (alpha-cyano-4-hydroxycinnamic acid) on the sample plate, which serves as a seeding ground for subsequent crystallization of a matrix/analyte mixture. Advantages of the ultra-thin layer method over other sample deposition approaches (e.g. dried droplet) are that it provides (i) greater tolerance to impurities such as salts and detergents, (ii) better resolution, and (iii) higher spatial uniformity. This method is especially useful for the accurate mass determination of proteins. The protocol was initially developed and optimized for the analysis of membrane proteins and used to successfully analyze ion channels, metabolite transporters, and receptors, containing between 2 and 12 transmembrane domains 2. Since the original publication, it has also shown to be equally useful for the analysis of soluble proteins. Indeed, we have used it for a large number of proteins having a wide range of properties, including those with molecular masses as high as 380 kDa 3. It is currently our method of choice for the molecular mass analysis of all proteins. The described procedure consistently produces high-quality spectra, and it is sensitive, robust, and easy to implement.

This video demonstrates the preparation of an ultra-thin matrix/analyte layer for analyzing peptides and proteins by Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS).

MALDI preparación de la muestra: el método de ultra capa fina

This video demonstrates the preparation of an ultra-thin matrix/analyte layer for analyzing peptides and proteins by Matrix-Assisted Laser Desorption ...

Investigación

Biología

Western Blotting Using the Invitrogen NuPage Novex Bis Tris MiniGels

Western Blotting (or immunoblotting) is a standard laboratory procedure allowing investigators to verify the expression of a protein, determine the relative amount of the protein present in different samples, and analyze the results of co-immunoprecipitation experiments. In this method, a target protein is detected with a specific primary antibody in a given sample of tissue homogenate or extract. Protein separation according to molecular weight is achieved using denaturing SDS-PAGE. After transfer to a membrane, the target protein is probed with a specific primary antibody and detected by chemiluminescence.
Since its first description, the western-blotting technique has undergone several improvements, including pre-cast gels and user-friendly equipment. In our laboratory, we have chosen to use the commercially available NuPAGE electrophoresis system from Invitrogen. It is an innovative neutral pH, discontinuous SDS-PAGE, pre-cast mini-gel system. This system presents several advantages over the traditional Laemmli technique including: i) a longer shelf life of the pre-cast gels ranging from 8 months to 1 year; ii) a broad separation range of molecular weights from 1 to 400 kDa depending of the type of gel used; and iii) greater versatility (range of acrylamide percentage, the type of gel, and the ionic composition of the running buffer).
The procedure described in this video article utilizes the Bis-Tris discontinuous buffer system with 4-12% Bis-Tris gradient gels and MES running buffer, as an illustration of how to perform a western-blot using the Invitrogen NuPAGE electrophoresis system. In our laboratory, we have obtained good and reproducible results for various biochemical applications using this western-blotting method.

This technical article describes a standard western-blotting procedure using the commercially available NuPAGE electrophoresis Mini-Gel system from Invitrogen.

Western Blot utilizando el Invitrogen NuPage Novex Bis Tris MiniGels

Western Blotting (or immunoblotting) is a standard laboratory procedure allowing investigators to verify the expression of a protein, determine the ...

Proteomic Sample Preparation from Formalin Fixed and Paraffin Embedded Tissue

Preserved clinical material is a unique source for proteomic investigation of human disorders. Here we describe an optimized protocol allowing large scale quantitative analysis of formalin fixed and paraffin embedded (FFPE) tissue. The procedure comprises four distinct steps. The first one is the preparation of sections from the FFPE material and microdissection of cells of interest. In the second step the isolated cells are lysed and processed using 'filter aided sample preparation' (FASP) technique. In this step, proteins are depleted from reagents used for the sample lysis and are digested in two-steps using endoproteinase LysC and trypsin. 
After each digestion, the peptides are collected in separate fractions and their content is determined using a highly sensitive fluorescence measurement. Finally, the peptides are fractionated on 'pipette-tip' microcolumns. The LysC-peptides are separated into 4 fractions whereas the tryptic peptides are separated into 2 fractions. In this way prepared samples allow analysis of proteomes from minute amounts of material to a depth of 10,000 proteins. Thus, the described workflow is a powerful technique for studying diseases in a system-wide-fashion as well as for identification of potential biomarkers and drug targets.

Archival formalin fixed and paraffin embedded (FFPE) clinical samples are valuable material for investigation of diseases. Here we demonstrate a sample preparation workflow allowing in-depth proteomic analysis of microdissected FFPE tissue.

Proteómica Preparación de muestras de formol fija y embebidos en parafina de tejidos

Preserved clinical material is a unique source for proteomic investigation of human disorders. Here we describe an optimized protocol allowing large scale ...

V3 Stain-free Workflow for a Practical, Convenient, and Reliable Total Protein Loading Control in Western Blotting

The western blot is a very useful and widely adopted lab technique, but its execution is challenging. The workflow is often characterized as a &#34;black box&#34; because an experimentalist does not know if it has been performed successfully until the last of several steps. Moreover, the quality of western blot data is sometimes challenged due to a lack of effective quality control tools in place throughout the western blotting process. Here we describe the V3 western workflow, which applies stain-free technology to address the major concerns associated with the traditional western blot protocol. This workflow allows researchers: 1) to run a gel in about 20-30 min; 2) to visualize sample separation quality within 5 min after the gel run; 3) to transfer proteins in 3-10 min; 4) to verify transfer efficiency quantitatively; and most importantly 5) to validate changes in the level of the protein of interest using total protein loading control. This novel approach eliminates the need of stripping and reprobing the blot for housekeeping proteins such as &#946;-actin, &#946;-tubulin, GAPDH, etc. The V3 stain-free workflow makes the western blot process faster, transparent, more quantitative&#160;and reliable.

V3 workflow is a western blot procedure using stain-free gels. The stain-free technology allows researchers to visualize protein separation quality, to verify the transfer efficiency, and most importantly, to validate the change in the protein of interest using total protein quantification as a reliable loading control.

Flujo de trabajo sin manchas V3 para un control de carga total de proteínas práctico, conveniente y confiable en Western Blotting

The western blot is a very useful and widely adopted lab technique, but its execution is challenging. The workflow is often characterized as a &#34;black ...

The Fastest Western in Town: A Contemporary Twist on the Classic Western Blot Analysis

The Western blot techniques that were originally established in the late 1970s are still actively utilized today. However, this traditional method of Western blotting has several drawbacks that include low quality resolution, spurious bands, decreased sensitivity, and poor protein integrity. Recent advances have drastically improved numerous aspects of the standard Western blot protocol to produce higher qualitative and quantitative data. The Bis-Tris gel system, an alternative to the conventional Laemmli system, generates better protein separation and resolution, maintains protein integrity, and reduces electrophoresis to a 35 min run time. Moreover, the iBlot dry blotting system, dramatically improves the efficacy and speed of protein transfer to the membrane in 7 min, which is in contrast to the traditional protein transfer methods that are often more inefficient with lengthy transfer times. In combination with these highly innovative modifications, protein detection using infrared fluorescent imaging results in higher-quality, more accurate and consistent data compared to the standard Western blotting technique of chemiluminescence. This technology can simultaneously detect two different antigens on the same membrane by utilizing two-color near-infrared dyes that are visualized in different fluorescent channels. Furthermore, the linearity and broad dynamic range of fluorescent imaging allows for the precise quantification of both strong and weak protein bands. Thus, this protocol describes the key improvements to the classic Western blotting method, in which these advancements significantly increase the quality of data while greatly reducing the performance time of this experiment.

This protocol explores the latest advancements in performing Western blot analyses.&#160;These novel modifications employ a Bis-Tris gel system with a 35&#160;min electrophoresis run time, a 7&#160;min dry blotting transfer system, and infrared fluorescent protein detection and imaging that generates higher resolution, quality, sensitivity, and improved accuracy of Western data.

El más rápido de Occidente en la ciudad: un toque contemporáneo en el análisis clásico de Western Blot

The Western blot techniques that were originally established in the late 1970s are still actively utilized today. However, this traditional method of ...

A Guide to Modern Quantitative Fluorescent Western Blotting with Troubleshooting Strategies

The late 1970s saw the first publicly reported use of the western blot, a technique for assessing the presence and relative abundance of specific proteins within complex biological samples. Since then, western blotting methodology has become a common component of the molecular biologists experimental repertoire. A cursory search of PubMed using the term &#8220;western blot&#8221; suggests that in excess of two hundred and twenty thousand published manuscripts have made use of this technique by the year 2014. Importantly, the last ten years have seen technical imaging advances coupled with the development of sensitive fluorescent labels which have improved sensitivity and yielded even greater ranges of linear detection. The result is a now truly Quantifiable Fluorescence based Western Blot (QFWB) that allows biologists to carry out comparative expression analysis with greater sensitivity and accuracy than ever before. Many &#8220;optimized&#8221; western blotting methodologies exist and are utilized in different laboratories. These often prove difficult to implement due to the requirement of subtle but undocumented procedural amendments. This protocol provides a comprehensive description of an established and robust QFWB method, complete with troubleshooting strategies.

The advancement of western blotting using fluorescence has allowed detection of subtle changes in protein expression enabling quantitative analyses. Here we describe a robust methodology for detection of a range of proteins across a variety of species and tissue types. A strategy to overcome common technical problems is also provided.

Una guía para la moderna cuantitativa fluorescente Western Blot con las estrategias de solución de problemas

The late 1970s saw the first publicly reported use of the western blot, a technique for assessing the presence and relative abundance of specific proteins ...

Mucin Agarose Gel Electrophoresis: Western Blotting for High-molecular-weight Glycoproteins

Mucins, the heavily-glycosylated proteins lining mucosal surfaces, have evolved as a key component of innate defense by protecting the epithelium against invading pathogens. The main role of these macromolecules is to facilitate particle trapping and clearance while promoting lubrication of the mucosa. During protein synthesis, mucins undergo intense O-glycosylation and multimerization, which dramatically increase the mass and size of these molecules. These post-translational modifications are critical for the viscoelastic properties of mucus. As a result of the complex biochemical and biophysical nature of these molecules, working with mucins provides many challenges that cannot be overcome by conventional protein analysis methods. For instance, their high-molecular-weight prevents electrophoretic migration via regular polyacrylamide gels and their sticky nature causes adhesion to experimental tubing. However, investigating the role of mucins in health (e.g., maintaining mucosal integrity) and disease (e.g., hyperconcentration, mucostasis, cancer) has recently gained interest and mucins are being investigated as a therapeutic target. A better understanding of the production and function of mucin macromolecules may lead to novel pharmaceutical approaches, e.g., inhibitors of mucin granule exocytosis and/or mucolytic agents. Therefore, consistent and reliable protocols to investigate mucin biology are critical for scientific advancement. Here, we describe conventional methods to separate mucin macromolecules by electrophoresis using an agarose gel, transfer protein into nitrocellulose membrane, and detect signal with mucin-specific antibodies as well as infrared fluorescent gel reader. These techniques are widely applicable to determine mucin quantitation, multimerization and to test the effects of pharmacological compounds on mucins.

Mucins are high-molecular-weight glycoconjugates, with size ranging from 0.2 to 200 megadalton (MDa). As a result of their size, mucins do not penetrate conventional polyacrylamide gels and require larger pores for separation. We provide a detailed protocol for mucin agarose gel electrophoresis to assess relative quantification and study polymer assembly.

La mucina en gel de agarosa de electroforesis: Western Blotting para glicoproteínas de alta peso molecular


Mucins, the heavily-glycosylated proteins lining mucosal surfaces, have evolved as a key component of innate defense by protecting the epithelium against ...

Sample Preparation for Mass Cytometry Analysis

Mass cytometry utilizes antibodies conjugated with heavy metal labels, an approach that has greatly increased the number of parameters and opportunities for deep analysis well beyond what is possible with conventional fluorescence-based flow cytometry. As with any new technology, there are critical steps that help ensure the reliable generation of high-quality data. Presented here is an optimized protocol that incorporates multiple techniques for the processing of cell samples for mass cytometry analysis. The methods described here will help the user avoid common pitfalls and achieve consistent results by minimizing variability, which can lead to inaccurate data. To inform experimental design, the rationale behind optional or alternative steps in the protocol and their efficacy in uncovering new findings in the biology of the system being investigated is covered. Lastly, representative data is presented to illustrate expected results from the techniques presented here.

This article describes the collection and processing of samples for mass cytometry analysis.

Preparación de muestras para análisis de masas Citometría

Mass cytometry utilizes antibodies conjugated with heavy metal labels, an approach that has greatly increased the number of parameters and opportunities ...

Sample Preparation and Imaging of Exosomes by Transmission Electron Microscopy

Exosomes are nano-sized extracellular vesicles secreted by body fluids and are known to represent the characteristics of cells that secrete them. The contents and morphology of the secreted vesicles reflect cell behavior or physiological status, for example cell growth, migration, cleavage, and death. The exosomes&#39; role may depend highly on size, and the size of exosomes varies from 30 to 300 nm. The most widely used method for exosome imaging is negative staining, while other results are based on Cryo-Transmission Electron Microscopy, Scanning Electron Microscopy, and Atomic Force Microscopy. The typical exosome&#39;s morphology assessed through negative staining is a cup-shape, but further details are not yet clear. An exosome well-characterized through structural study is necessary particular in medical and pharmaceutical fields. Therefore, function-dependent morphology should be verified by electron microscopy techniques such as labeling a specific protein in the detailed structure of exosome. To observe detailed structure, ultrathin sectioned images and negative stained images of exosomes were compared. In this protocol, we suggest transmission electron microscopy for the imaging of exosomes including negative staining, whole mount immuno-staining, block preparation, thin section, and immuno-gold labelling.

This protocol describes the various techniques necessary for transmission electron microscopy including negative staining, ultrathin sectioning for detailed structure, and immuno-gold labelling to determine the positions of specific proteins in exosomes.

Preparación de la muestra y proyección de imagen de exosomas por microscopía electrónica de transmisión

Exosomes are nano-sized extracellular vesicles secreted by body fluids and are known to represent the characteristics of cells that secrete them. The ...

Miniaturized Sample Preparation for Transmission Electron Microscopy

Due to recent technological progress, cryo-electron microscopy (cryo-EM) is rapidly becoming a standard method for the structural analysis of protein complexes to atomic resolution. However, protein isolation techniques and sample preparation methods for EM remain a bottleneck. A relatively small number (100,000 to a few million) of individual protein particles need to be imaged for the high-resolution analysis of proteins by the single particle EM approach, making miniaturized sample handling techniques and microfluidic principles feasible.
A miniaturized, paper-blotting-free EM grid preparation method for sample pre-conditioning, EM grid priming and post processing that only consumes nanoliter-volumes of sample is presented. The method uses a dispensing system with sub-nanoliter precision to control liquid uptake and EM grid priming, a platform to control the grid temperature thereby determining the relative humidity above the EM grid, and a pick-and-plunge-mechanism for sample vitrification. For cryo-EM, an EM grid is placed on the temperature-controlled stage and the sample is aspirated into a capillary. The capillary tip is positioned in proximity to the grid surface, the grid is loaded with the sample and excess is re-aspirated into the microcapillary. Subsequently, the sample film is stabilized and slightly thinned by controlled water evaporation regulated by the offset of the platform temperature relative to the dew-point. At a given point the pick-and-plunge mechanism is triggered, rapidly transferring the primed EM grid into liquid ethane for sample vitrification. Alternatively, sample-conditioning methods are available to prepare nanoliter-sized sample volumes for negative stain (NS) EM.
The methodologies greatly reduce sample consumption and avoid approaches potentially harmful to proteins, such as the filter paper blotting used in conventional methods. Furthermore, the minuscule amount of sample required allows novel experimental strategies, such as fast sample conditioning, combination with single-cell lysis for &#34;visual proteomics,&#34; or &#34;lossless&#34; total sample preparation for quantitative analysis of complex samples.

An instrument and methods for the preparation of nanoliter-sized sample volumes for transmission electron microscopy is presented. No paper-blotting steps are required, thus avoiding the detrimental consequences this can have for proteins, significantly reducing sample loss and enabling the analysis of single cell lysate for visual proteomics.

Preparación de muestras miniatura para microscopia electrónica de transmisión

Due to recent technological progress, cryo-electron microscopy (cryo-EM) is rapidly becoming a standard method for the structural analysis of protein ...