Protein visualization on gels
Immediately after electrophoresis proteins in the gels are precipitated by either adding alcohol containing solutions or strong acids (e.g. TCA).
Protein are often stained by Coomassie Blue dye or by photography-like treatment with AgNO3 (silver staining)
There are many other stains available (e.g. Stains-all, fluorescence probes etc.)
Example of silver stained gel
Silver staining is usually 10-100 times more sensitive than Coomassie Blue staining, but it is more complicated.
Faint but still visible bands on this gel contain less than 0.5 ng of protein!
Native PAGE
Separates folded proteins and protein-protein or protein-ligand complexes by charge, size, and shape
Useful for:
Examining protein-protein protein-ligand interactions
Detecting protein isoforms/conformers
Native PAGE examples
