Dot blot protocol
General dot blot procedure.
A technique for detecting, analyzing and identifying proteins, similar to the western blot technique but differing in that protein samples are not separated electrophoretically but are spotted through circular templates directly onto the membrane or paper substrate.
Concentration of proteins in crude preparations (such as culture supernatant) can be estimated semiquantitatively by using the dot blot method if you have both purified protein and specific antibody against it.
20 mm Tris-HCl
150 mm NaCl
0.05% Tween 20 in TBS
0.1% BSA in TBS-T
Nitrocellulose membrane (BIO-RAD, Trans-Blot, etc.)