Synthetic rabbit-human antibody conjugate as a control in immunoassays for immunoglobulin M specific to hepatitis E virus.
BACKGROUND
In assays for anti-hepatitis E virus (HEV) immunoglobulin M (IgM), large volumes of the patient's sera cannot be easily obtained for use as a positive control. In this study, we investigated an alternative chemical method in which rabbit anti-HEV IgG was conjugated with human IgM and was used as a positive control in the anti-HEV IgM assay. Rabbit anti-HEV IgG was isolated from immune sera by chromatography on protein A-Sepharose and was conjugated with human IgM by using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) as a crosslinker.


RESULTS
The specific anti-HEV IgG antibody titer was 100,000 times that of the negative control, i.e., prebleed rabbit serum. The results of anti-HEV IgM enzyme-linked immunosobent assay showed that the antibody conjugate was similar to anti-HEV IgM antibodies produced in humans. The results of a stability experiment showed that the antibody conjugate was stable for use in external quality assessment or internal quality control trials.


CONCLUSIONS
We concluded that the chemically conjugated rabbit-human antibody could be used instead of the traditional serum control as a positive control in the anti-HEV IgM assay.
Zhang
Kuo
K
National Center for Clinical Laboratories, Beijing Hospital, Beijing, PR China.
Wang
Lunan
L
Liu
Min
M
Zhang
Rui
R
Li
Jinming
J
D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards*; D006508:Hepatitis Antibodies / Q000032:analysis* / Q000737:chemistry; D016751:Hepatitis E / Q000097:blood* / Q000276:immunology; D016752:Hepatitis E virus / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000737:chemistry; D007075:Immunoglobulin M / Q000032:analysis* / Q000737:chemistry; D011817:Rabbits; D012015:Reference Standards
D006508:Hepatitis Antibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M