ABSTRACT
Nine serial three-fold dilutions (1:1 to 1:6561) were prepared from 18 sera obtained from hemophiliacs confirmed to have antibodies to the human immunodeficiency virus. The dilutions were tested with five different commercial enzyme immunoassay kits and twelve sera were retested 5 to 7 months later by different lots of three kits. The dilution that gave an absorbance (OD) equal to the cut-off OD was considered as the titer of antibody. Sensitivities of the kits were compared by statistical and regression analysis; the same approach was used for studying reproducibility from the results of retesting. The highest titers were found with the Wellcome kit, the lowest with Organon and Pasteur kits, whereas intermediate values were found with the Sorin/Biomedica and Electronucleonics kits. With the Organon and Wellcome kits, excellent reproducibility was observed on later retesting; however, a significant change in titers was seen on retesting the Sorin kit.
