Development of a radial immunodiffusion technique employing monoclonal antibodies for apolipoprotein B determination in human plasma.

Twenty monoclonal antibodies obtained from two different fusions of SP2/0-Ag 14 cell line (non-secretor hybridoma) with human plasma low density lipoproteins have been selected. We found that a mixture formed by the 20 monoclonal antibodies was able to form a single precipitin line with human plasma low density lipoproteins by a double gel diffusion technique. Further studies revealed that only two monoclonal antibodies were needed to precipitate low density lipoproteins in gel. However, a minimum of four particular monoclonal antibodies was required to obtain an optimal precipitin ring and a linear standard curve within 24 h using a radial immunodiffusion technique. We have then compared the radial immunodiffusion performed with a monoclonal antibody mixture to those employing conventional goat and rabbit antibodies in terms of plasma apolipoprotein B determinations. The apolipoprotein B values determined by monoclonal antibodies significantly correlate with the values obtained by the technique using goat (r = 0.95; p less than 0.001) and rabbit (r = 0.95; p less than 0.001) antibodies. Our data indicate that a mixture of monoclonal antibodies can mimic conventional antibodies in terms of immunoprecipitation and apolipoprotein B determination.