SDSPAGEvarianten
SDS-PAGE is a widely used method for separating proteins by molecular weight under denaturing conditions. Variants of SDS-PAGE refer to changes in gel composition, buffers, or sample preparation designed to improve resolution for certain protein classes or experimental needs. The core principle—SDS denatures proteins and imparts a roughly uniform negative charge, allowing separation by size in a polyacrylamide gel—remains the same.
Gel composition and format: common variants use fixed percentages (for example 8–12% acrylamide) or gradient gels
Buffer systems: the traditional Laemmli system uses Tris-Glycine-SDS buffers. Alternatives include Tris-Tricine-SDS, which improves resolution for
Reducing versus non-reducing: many variants run samples under reducing conditions with DTT or beta-mercaptoethanol to break
Two-dimensional PAGE and other adaptations: A major variant is two-dimensional PAGE, in which an initial isoelectric
Choosing a variant depends on protein properties, desired resolution, and available equipment.