Effect of pretreatment of wells in polystyrene plates on adsorption of some human serum proteins.

Coating of Immulon polystyrene plates with 0.2% casein in phosphate buffered saline (PBS) completely abolishes adsorption of human serum proteins to these plates. However, pretreatment of such plates with PBS or 0.15 M NaCl in deionized water (10 microS) before coating makes possible adsorption of human immunoglobulins G (HIgG) and M but not serum albumin (HSA) and transferrin (HTrf). Effect of pretreatment with PBS on adsorption of HIgG is long-term and rather stable. Results of experiments with radioiodinated HIgG, mouse IgG, HSA and human chorionic gonadotropin confirm the peculiar effect of pretreatment with PBS on casein coating. Pretreatment with deionized water, instead of PBS, markedly diminish adsorption but tap or commercial spring waters (> 1000 microS), even without 0.15 M NaCl, affect adsorption similarly to PBS in deionized water. Super pure water (0.05 microS) even with NaCl used for pretreatment does not influence adsorption of HIgG to plates coated with casein. Distinct differences in adsorption of HIgG and HTrf was demonstrated using solutions for ELISA prepared from super pure, deionized and tap waters.