Rapid method for assay of quantitative binding of soluble proteins and photosynthetic membrane proteins on poly(vinylidene difluoride) membranes

For quantitative immunoassay on transfer membranes, a rapid and reliable method was developed whereby more than 90% of proteins are retained on poly(vinylidene difluoride) (PVDF) membranes. Binding of proteins on PVDF was assessed for a photosynthetic membrane and soluble cell extracts from the cyanophyte Synechocystis PCC6714, and with bovine serum albumin and rabbit serum. Binding of protein samples to PVDF was much better than by the capillary-draw or vacuum-filtration methods. Further, for enzyme immunoassays the PVDF procedure developed here allows detection of antigens in the μg range in crude protein samples.