Establishment and primary application of double antigen sandwich ELISA for detection of hepatitis E virus antibody

Aim To establish a double antigen sandwich ELISA(DS ELISA)for detection of anti hepatitis E virus antibody in different animals.Methods A recombinant antigen expressed in E.coli. was used to coate microplate and conjugated with HRP respectively,the conditions of DS ELISA were determined using five HEV antibody positive sera and forty antibody negative sera.The accordance of DS ELISA with indirectly IgG ELISA was compared by paralleling detection of 400 blood donors'sera using both kits.The serial sera of three HEV experimental infected monkeys were detected using the DS ELISA and IgG ELISA kit of Genelabs Co.Some cattle,sheep,goat,swine,and chicken sera were also detected with DS ELISA.Results DS ELISA for detection of anti HEV were established.The results of parallel detection of 400 blood donor's sera by DS ELISA and indirectly IgG ELISA showed that these two kit had good accordance,and the signal/cutoff(s/co)value of DS ELISA was higher than indirectly ELISA.When detecting serial sera of experimental infected monkey,the seraconversion time detected with DS ELISA were much earlier than with a well known commercial IgG ELISA kit,and the antibody's positive period and the titer detected by DS ELISA were better than the commercial kit too.Anti HEV antibodies were found in all kinds of animals detected,the positive rate in swine was the highest.Conclusion A double antigen sandwich ELISA have been established using recombinant antigens expressed in E.coli.,and can be used to detect anti HEV in different kinds of animals.