An enzyme-linked immunosorbent assay for measuring antibody titre against avian reovirus using a single dilution of serum.

An indirect enzyme-linked immunosorbent assay (ELISA) is described to measure antibody titres to avian reovirus in a single dilution of serum. Various methods of antigen coating were compared. Overnight treatment of plates at 4 C with antigen diluted in 0.01 M phosphate buffered saline, pH 7.5 appeared to be the most suitable as it increased the sensitivity and specificity of the test. Standard curve equations derived from linear regression analyses of predetermined end-point titres versus absorbances were employed to predict antibody titres from raw absorbances, corrected absorbances, specific absorbances, sample/positive ratios and sample/negative ratios measured in a single dilution of serum. The specific absorbance and sample/positive ratio appeared to be the most suitable because of their better performance and stability in predicting titres. In a trial a significant positive correlation was observed between the titres measured by ELISA and virus neutralisation test.