Decline in specificity of the ELISA due to storage of serum, and its recovery by adsorption with kaolin.
Several laboratories have experienced problems with the enzyme-linked immunosorbent assay (ELISA) due to non-specific background binding of human sera, but no general solution has been introduced. In this study the ELISA was used to measure antibody to herpes simplex virus in human sera which had been stored at -20 degrees C for up to 3 years, and the specificity was assessed by comparing the absorbance achieved with the virus neutralization titer. The severity of background binding was minimal in sera which had been obtained recently, but increased with storage time and gradually eliminated the specificity of the assay. When sera were adsorbed with kaolin, background binding of all sera was markedly reduced and the specificity was restored.
D000327:Adsorption; D000914:Antibodies, Viral / Q000032:analysis*; D001793:Blood Preservation; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007124:Immunoenzyme Techniques; D007616:Kaolin; D009500:Neutralization Tests; D018139:Simplexvirus / Q000276:immunology*; D013997:Time Factors
D000914:Antibodies, Viral; D007616:Kaolin