Which technique combines SDS-PAGE and isoelectric focusing?

The technique that combines SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) and isoelectric focusing is known as 2D gel electrophoresis. This method allows for the separation of proteins based on two distinct properties: molecular weight and isoelectric point.

In the first dimension, isoelectric focusing separates proteins according to their isoelectric point, where proteins migrate in a pH gradient until they reach the pH at which they carry no net charge. Following this initial separation, the gel is subjected to SDS-PAGE in the second dimension, which separates the proteins by size. This two-dimensional approach allows for a more comprehensive analysis of complex protein mixtures, enabling researchers to distinguish between different proteins even if they are of similar sizes or isoelectric points.

By utilizing both methods, 2D gel electrophoresis provides high-resolution separation and is particularly valuable for proteomic studies, where the identification and quantification of numerous proteins in complex samples are crucial. This makes it a powerful technique in the field of biochemistry and molecular biology.