STUDY ON THE DETECTION OF TOXOPLASMACIRCULATING ANTIGENS USING IMMUNO-PCR / 中国人兽共患病学报

ABSTRACT

Aim to explore an assay for the early diagnosis of Toxoplasma infection. Methods Free streptavidin was used to attach a biotinylated DNA to the biotinylated second antibody, through amplication of the DNA label, antigen which bound with antibodies was detected, thus Toxoplasma circulating antigens Immuno-PCR assay was estabished. detecting the CAg in serial dilutions of serum and the dynamic variation of serum CAg of Toxoplasma in experimental infected mice using Immuno-PCR and ELISA parallely to compare the sensitivity Result The detection limit of the immuno-PCR was at about 1/1000 dilution, it was at 1/5 dilution for ELISA. CAg of Toxoplasma could be detected as early as the third day after infection using Immuno - pcr, Wheareas the ELISA on the same samples, revealed no detectable CAg elevations until fifth day after infection. Conclusion In comparison with CAgdetecting by ELISA parallelly performed, this method is more sensitive than ELISA, The detection limit of the immuno-PCR was an 200 fold improvement compared with a conventional ELISA. the positive result could be detected earlier than that of ELISA,It provide scientific basis for early diagnosis of Toxoplasmosis.