Complement factor adsorption on solid surfaces--an ellipsometric method for investigation of quantitative aspects.

An optical method, ellipsometry, has been used for quantification of organic material adsorbed from complement sufficient sera on antibody coated solid surfaces. Maximal adsorption of organic material from complement sufficient human sera occurred at about 0.5 micrograms/cm2 of IgG. C3 but not C5, C8 or C9 was detected on the antibody surface incubated with complement sufficient sera. This may indicate that IgG adsorbed on methylized silicon surfaces lack binding sites for complement factors beyond C3. A modification of the method was also used for quantification of migration inhibition of human polymorphonuclear leucocytes (PMNL). Locomotion inhibition fell in a sharp interval from 0.2 to 0.5 micrograms/cm2 of IgG on the surface. We believe that the suggested type of measurements is important for understanding the quantitative relationships between humoral effects such as antibody dependent complement activation and cellular effects such as migration of PMNL.