The HBV markers and HBV DNA in poultry sera, Yolk and bovine milk whey were detected by reversed passive hemagglutination assay (RPHA), enzyme immunoassay (EIA) and polymerase chain reaction (PCR).

In this paper, an attempt to use the reverse passive haemagglutination assay (RPHA) to identify the predators of cotton aphid Aphis gossypii Glover was described.