Tween 20 removes antibodies and other proteins from nitrocellulose.

It has generally been assumed that the binding of most proteins to nitrocellulose is stable in the non-ionic detergent Tween 20. However, the following paper demonstrates that in immunoassays where antibodies or other proteins are bound directly to the nitrocellulose, 0.05% Tween 20 may dissociate these proteins from the membrane. The degree of dissociation appears to be dependent on the individual protein studied. Some antibodies and other proteins bind tightly to nitrocellulose and dissociation of these proteins by Tween 20 is barely detectable. In contrast, other proteins are nearly completely stripped from the nitrocellulose by the same detergent. Therefore, unless it is known from control experiments what proteins will or will not be dissociated from nitrocellulose by Tween 20, the routine use of Tween 20 in the development of Western blots, native blots and dot-blots should be discontinued.