Improved ELISA for the detection of adenovirus antigen in faeces extracts by the biotin/streptavidin interaction.

Two enzyme-linked immunosorbent assays for detection of adenovirus antigen in faecal extracts have been established. A conjugate of rabbit anti-(human) adenovirus immunoglobulin and horseradish peroxidase (HRP) prepared by means of a hetero-bifunctional reagent, N-succinimidyl-3-(2-pyridyldithio) propionate (SPDP), was used in the conventional ELISA, and a biotin-labelled antibody in combination with a streptavidin/peroxidase complex in the other (BS-ELISA). A collection of 60 faecal extracts, in which adenovirus had been demonstrated by immunosorbent electron microscopy (ISEM) in 29 samples, was selected and examined by ELISA and BS-ELISA. The presence of adenovirus was demonstrated in 38 (63%) of the samples by BS-ELISA compared to 34 (58%) by ELISA, showing the advantage of the biotin/streptavidin system for setting up ELISA assays. Comparison of the three different techniques showed that the biotin/streptavidin (BS-ELISA) is the most sensitive assay for detection of adenovirus antigen in faecal samples.