Western Blot Membrane Incubation with NP-40?

[admin]

Email question from a user:

When performing a ligand blot analysis, under non-reducing conditions, after western blotting, the nitocellulose membrane is incubated in 3% NP-40 for half hour, followed by blocking in BSA in 0.1% Tween PBS. I have come across many papers where NP40 is used. Can you explain to me why this is done?

Thank you.

Kind regards.

(posted by admin)

[danfive]

Because both NP-40 (Igepal) and Tween-20 are both weak nonionic surfactants used in wash solutions for Westerns, ISH, Dot-blots, ELISA. Along with Triton X; another nonionic surfactant, they dissolve easily in TBS, or PBS solutions.

[danfive]

For more background you may want to read "A Guide to the Properties and Uses of Detergents in Biology and Biochemistry" by Srirama M. Bhari
--> http://www.biology.ucsd.edu/classes/...oklet_2001.pdf