In-gel protein digestion (protocol from Bruker)

SYPRO Ruby gel staining (protocol from Invitrogen)

iTRAQ labeling of peptides (protocol from Applied Biosystems)

Enhanced Coomassie staining protocol: PMID: 19684561 or PMID: 20162584

 TIPS TO AVOID KERATIN CONTAMINATION WHEN PERFORMING SDS-PAGE

• Keratin contamination is nearly impossible to completely avoid, and becomes more prominent when the proteins-of-interest are at low levels.
• Always use NON-LATEX gloves and wear lab coats. 
• Use the highest grade reagents possible (i.e. proteomics or mass spec grade). DTT, beta-mercaptoethanol and buffers are common sources of keratin.
• Wash all glass plates thoroughly with 70% ethanol prior to casting an SDS-PAGE gel. 
• After completing electrophoresis, disassemble in a laminar flow hood. 
• Avoid storing gel in SARAN WRAP or similar material and instead use new, cleaned plastic or glass gel trays.
• De-stain the gel in a clean container that has been rinsed thoroughly with 70% ethanol or methanol/acetonitrile.
• When excising gel slices, use fresh razor blades and nitrile gloves in a laminar flow hood.