4.2.2 Two-dimensional gel electrophoresis
Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) separates
proteins based on both mass and charge, allowing precise protein
analysis. It can characterize around 5,000 distinct proteins depending
on gel size. Proteins are dissociated based on their charge followed by
their mass in first and second dimensions respectively. This technique
is used for studying biochemical processes, post-translational
modifications, and protein alterations [53]. The process involves
five steps: sample preparation, first separation, linking, second
separation, and protein identification. Isoelectric focusing usually
precedes SDS electrophoresis. The traditional order is preferred for
practical reasons, as SDS gels are easier to work with and compatible
with downstream analysis methods like mass spectrometry [54].