DETECTION OF ANTIBODIES TO THE HIV-1 P25 24 AND GP120 PROTEINS BY SPHERE-LINKED IMMUNODIAGNOSTIC ASSAY (SLIDA)/

In this paper, we have used the technique known as sphere-linked immun odiagnostic assay (SLIDA)for the detection of antibodies to HIV-1 p25/ 24 and gp120 proteins. In this technique, the p25/24 and gp120 protein s were covalently bonded to 0.5 mum carboxylated microspheres. They we re then exposed to serial dilutions of rabbit antiserum to HIV-1 p25/2 4, sheep antiserum to gp120 and dilutions of the corresponding normal sera. Specific immunolabeling was monitored by using gold-labeled seco ndary antibody. The gold particles bound to the microspheres were an i ndication for the presence of specific antibody in the serum sample. T he gold-labeled microspheres were photographed using a transmission el ectron microscope, and the number of gold particles bound to the micro spheres were counted manually using the electron micrographs. The spec ificity and sensitivity of the technique were then compared to enzyme- linked immunosorbent assay (ELISA) and Western blotting.