Efficacy of passive transfer of proteins from preparative polyacrylamide gels to nitrocellulose membranes.

Passive transfer of proteins from preparative polyacrylamide gels to nitrocellulose membrane (NTC) was investigated. The transfer was carried out without the removal of sodium dodecyl sulphate from the denaturing gels. The transfer was quick, easy to perform, and does not require any apparatus. More than one replica of the same band can be obtained by successive transfer to more than one NTC without significantly affecting the Coomassie Brilliant Blue (CBB) staining ability of protein bands left in the gel. A fraction of protein transferred passively in the absence of electrical current from as low as 1.5 micrograms of protein per band in a 2 mm thick gel was found sufficient for detection with amido black staining, and more so by immunostaining. The method was found highly satisfactory for seven proteins (14 kDa to 66 kDa) checked in the present study and can be adopted, after checking its efficacy for any protein, for routine qualitative tests.