Solutions tampons de pH

<p>Tris is a buffering agent with an optimal pH range of 7.1-9.1 and a pKa of 8.07. It is used to prepare buffer solutions within physiological pH range and is suitable for western blot and nucleic acid electrophoresis. This buffer also forms metal chelates.</p>

<p>HEPES, also known as 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, is a piperazinic buffer with an optimal pH range of 6.8-8.2 and a pKa of 7.48. This zwitterionic buffering agent is widely used in cell culture however when exposed to light HEPES can produce hydrogen peroxide.</p>

<p>Tris-HCl is the same as Tris base with the addition of HCl. It is used as a buffering agent to prepare buffer solutions.</p>

<p>3-(Cyclohexylamino)-1-propanesulfonic acid, also known as CAPS is a zwitterionic biological buffering agent with an optimal pH range of 9.7 to 11.1 and a pKa of 10.4. It is useful for the extraction of proteins from biological samples and for studying enzyme kinetics at high pH.</p>

<p>BES, also known as 2-[N,N-Bis-(2-hydroxyethyl)amino]ethanesulfonic acid, is a buffering agent that forms complexes with DNA and certain metal ions, It has an optimal pH range of 6.4-7.8 and a pKa of 7.09.</p>

<p>TAPS, also known as 3-[(Tris(hydroxymethyl)methyl)amino]-1-propanesulfonic acid, is a buffering agent that can be used in capillary electrophoresis with DNA and can form metal complexes. It has an optimal pH range of 7.7-9.1 and a pKa of 8.4.</p>

A ready-to-use 5X solution with beta-mercaptoethanol as a reducing agent. Used in SDS-PAGE for loading of conventional proteins. The use of Laemmli sample buffer ensures optimal band resolution when preparing proteins for SDS-PAGE with Tris-glycine-SDS running buffer. Role of 5X SDS PAGE Sample buffer :1. Tris is a buffer and it’s pH plays an essential role in preserving peptide bonds from breaking apart. 2. Sodium dodecyl sulphate is an anionic detergent that helps in linearizing (by denaturing) the proteins and bringing a net negative charge to the proteins irrespective of the initial charge. 3. The high density of glycerol ensures the sample moves down into the well. 4. Beta-mercaptoethanol, along with SDS, ensure the bands are individual polypeptide instead of molecular complexes. 5. The dye visually indicates the location (tracking) of the sample in the gel.

It is the most commonly used sample buffer for SDS-PAGE of non-denatured proteins It is a ready-to-use 5X solution without dithiothreitol (DTT) and Beta-mercaptoethanol (BME) as a reducing agent. This buffer can be used as a loading buffer in all kinds of denaturing gels and are compatible with Coomassie, silver staining and Western blotting. The 5X concentration of this buffer facilitates the loading of larger sample volume per well compared to the traditional 2X loading buffer.Role of reagents: Tris-HCl: as a buffering substance. The pH play an essential role in preserving peptide bonds from breaking apart. SDS: Proteins comes in different sizes and charges. SDS is an anionic detergent that helps in linearizing (by denaturing) the proteins and bringing a net negative charge to the proteins irrespective of the initial charge. Glycerol: The high density (thickening of the solution) of glycerol ensures the sample moves down into the well. Bromophenol Blue: visually indicates the location (tracking dye) of the sample in the gel.

It is the most commonly used sample buffer for SDS-PAGE of denatured proteins. It is a ready-to-use 5X solution with dithiothreitol (DTT) as a reducing agent. It can be used for SDS-PAGE protein loading of conventional proteins. The use of sample buffer ensures optimal band resolution when preparing proteins for SDS-PAGE with Tris-glycine-SDS running buffer. :It is the most commonly used sample buffer for SDS-PAGE of denatured proteins. It is a ready-to-use 5X solution with dithiothreitol (DTT) as a reducing agent. It can be used for SDS-PAGE protein loading of conventional proteins. The use of sample buffer ensures optimal band resolution when preparing proteins for SDS-PAGE with Tris-glycine-SDS running buffer. :It is the most commonly used sample buffer for SDS-PAGE of denatured proteins. It is a ready-to-use 5X solution with dithiothreitol (DTT) as a reducing agent. It can be used for SDS-PAGE protein loading of conventional proteins. The use of sample buffer ensures optimal band resolution when preparing proteins for SDS-PAGE with Tris-glycine-SDS running buffer.Role of reagents: Tris-HCl: as a buffering substance. The pH play an essential role in preserving peptide bonds from breaking apart. SDS: Proteins comes in different sizes and charges. SDS is an anionic detergent that helps in linearizing (by denaturing) the proteins and bringing a net negative charge to the proteins irrespective of the initial charge. Glycerol: The high density (thickening of the solution) of glycerol ensures the sample moves down into the well. DL-Dithiothreitol (DTT): is a strong reducing agent. Its specific role in sample denaturation is to remove the last bit of tertiary and quaternary structure by reducing disulfide bonds. Bromophenol Blue: visually indicates the location (tracking dye) of the sample in the gel.