Effect of Heterology on Polyclonal and Monoclonal antibodies in the detection of Amphetamine, Methamphetamine and Ephedrine by membrane immunoassays

Abstract

The detection of amphetamine, methamphetamine and ephedrine by heterologous immunoassay was investigated through polyclonal antibodies raised from the derivatives of amphetamine, methamphetamine and ephedrine namely N-(3-aminopropyl)amphetamine, N-(4-aminobutyl)amphetamine, N-(3-aminopropyl)methamphetamine, N-(4-aminobutyl)methamphetamine, N-(3-aminopropyl)ephedrine, and N-(4-aminobutyl) ephedrine. Only the selected antibody was transferred to heterologous immunoassay using monoclonal antibody. By comparison, only the selected immunoassay was developed to membrane immunoassay. These investigations confirmed the effect of heterologous immunoassay with polyclonal antibody on sensitivity and specificity of either amphetamine, methamphetamine or ephedrine detection. Three combinations of antiserum and enzyme-label showed significantly detection of methamphetamine with ephedrine, ephedrine and amphetamine. Monoclonal antibody raised showed less sensitivity and specificity for amphetamine, methamphetamine and ephedrine than polyclonal antibody due to the tight binding of immunogen hapten to monoclonal antibody. By lateral flow technique, membrane immunoassay using polyclonal antibody could be utilized for methamphetamine and ephedrine detection at the cut-off of 1,000 and 500µg/L, respectively. It was therefore concluded that heterologous immunoassay using polyclonal antibody would be fruitful for membrane immunoassay development. For monoclonal antibody, the selection of the effective clone would be the main concerned for managing heterologous developed. The membrane immunoassay would possibly be further developed to practical immunoassay test-kit.