Staining of proteins on membranes

Nitrocellulose-bound proteins can be stained with amido hlack lOB (Towbin et al., 1979), CBB (Burnette, 1981), and several other dyes (aniline black. Ponceau S, fast green, toluidine blue Gershoni and Palade, 1983). The recently developed immunostain for proteins on nitrocellulose filters (Wojtkowiak et al., 1983) is very sensitive (Section 16.3.1). 

Nitrocellulose membranes are not very stable in acidic methanol and prolonged use of such solvents should be avoided. Staining with CBB is carried out in 40% methanol, 10% acetic acid and 0.2% dye for 5 min. Destaining is performed rapidly (2 min) in 90% methanol. Alternatively, 0.1% amido black lOB in 45% methanol and 10% acetic acid can be used for 5 min, followed by a 2-3 min destaining with 90% methanol and 2% acetic acid. 

---