Enzyme-immunoassay in the diagnosis of human hepatitis A: specific and non-specific reactions.
Solid-phase enzyme-immunoassay (EIA) used for the detection of hepatitis A virus (HAV) often reveals a non-specific activity which can be reduced or fully eliminated in the presence of normal serum. The factor responsible for this activity appeared to be a non-viral EIA-active material (NVEAM) that non-specifically reacted with normal serum of some mammalian species (human, monkey, rabbit, cattle). The HAV and NVEAM have been separated by CsC1 gradient centrifugation, where the HAV banded in a narrow zone at 1.34 g/cm3, whereas the NVEAM could be found in a wider zone with an average density of 1.31 g/cm3. Non-immunological character of the non-specific activity was demonstrated by the inhibitory effect of weak non-ionic detergents (0.05% Tween 20 or bile, 1:500). The conditions for preferential binding of the HAV by immune sera and elimination of non-specific reaction have been determined.
D000818:Animals; D000956:Antigens, Viral / Q000032:analysis; D002499:Centrifugation, Density Gradient; D003902:Detergents / Q000494:pharmacology; D005243:Feces / Q000032:analysis* / Q000382:microbiology; D006506:Hepatitis A / Q000175:diagnosis*; D006507:Hepatovirus / Q000276:immunology; D006801:Humans; D007124:Immunoenzyme Techniques
D000956:Antigens, Viral; D003902:Detergents