Quantitative and qualitative detection of cytomegalovirus-specific antibodies using two types of enzyme-linked immunosorbent assay

An indirect ELISA and an inhibition ELISA were developed for the detection of cytomegalovirus (CMV)-specific immunoglobulin G (IgG) and CMV-specific total immunoglobulin, respectively. Both assays were more specific than the complement fixation (CF) test, and titres of positive sera were 660 times higher by IgG ELISA and 6 times higher by inhibition ELISA than titres by the CF test. Titres by IgG ELISA were reliably determined using the absorbance obtained at a single serum dilution of 1/1,000 in conjunction with a standard graph. Both ELISAs compared favourably with each other in sensitivity and specificity in determining CMV immune status. The inhibition ELISA, in particular, provides a simple and reliable method of screening sera, which requires no control antigen or predilution of sera. It should prove useful for large-scale screening procedures, such as blood donor testing.