Standardization of an Enzymometric Assay for Apolipoprotein A-I by Using Mixtures of Monoclonal Antibodies

Christine Betard, Ngoc Vu-Dac, Hafid Mezdour, A. Christine Nestruck, A. Leroy, J.-Ch. Fruchart
1987 Clinical Chemistry and Laboratory Medicine  
For the Standardization of human plasma apolipoprotein A-I assay two well characterized monoclonal antibody mixtures were used to develop a sandwich immunoenzymometric assay. The monoclonal antibody mixture l (A05-A17-A30) in solid phase technique was selected on the basis of its higher binding capacity of [ 125 I]HDL (41 ng per well) compared to polyclonal antibody (23 ng per well). The epitopes recognized by monoclonal antibody mixture l are surface antigenic sites of apolipoprotein A-I
more » ... poprotein A-I expressed on native HDL äs determined by competitive imhibition of labeled HDL. The peroxidase conjugated monoclonal antibody mixture 2 (A03-A05-A17-A51) was selected on the basis of its ability to bind to apolipoproteincaptured by monoclonal antibody mixture 1. For this, we used the 125 I-labeled monoclonal antibodies. Under optimized assay cönditioiis, the immunoenzymometric assay is precise (intra-and inter-assay coefficients of variations 5.4% and 9.2% respectively). It yields plasma apolipoprotein A-I values that correlate highly with those obtained with polyclonal antibody (r = 0.96). So the use of well characterized monoclonal antibody mixtures reacting only to surface antigenic sites of apolipoprotein A-I present on native lipoprotein may provide the possibility öf Standardization of apolipoprotein A-I measurement.
doi:10.1515/cclm.1987.25.12.893 fatcat:3w6lg2ahijd7zikx6ylmvgflhy