A method for preparing a microbead suspension for use in an assay for determining the presence of antibodies to human immunodeficiency virus in a sample and an assay using the microbead suspension

摘要

An HIV antigen coated microbead suspension for use in an assay for determining the presence of antibodies to a specific HIV virus in a blood or other sample is prepared by initially precoated polstyrene microbeads with bovine serum albumin. The HIV antigen is acylated in a citraconic anhydride solution for solubilising thereof, and the acylated solution of the HIV antigen is addded to a 5% suspension of the precoated mircobeads in a 50 mM carbonate buffer solution for coating the HIV antigen onto the precoated microbeads. The acylated HIV antigen coated microbeads in the buffer solution are incubated for eighteen to twenty four hours at a tempature of 21C to 25C, and the HIV antigen coated onto the microbeads is deacylated in a 50 mM citric acid buffer solution of pH in order of 4.8 and mixed and incubated for eighteen to twenty-four hours at a temperature of 35C to 39C to complete the decaylation. After washing the deacylated HIV antigen coated microbeads are suspended in a 50mM Tris/polyethylene glycol buffer solution of pH in the order of 8.63, and the HIV antigen coated microbead suspension is further diluted to 0.375% using 800 mM Tris/1% bovine serum albumin of pH of 8.5 with constant stirring. The microbead suspension is maintained at a temperature in the range of 2C to 8C for a minimum of one week for equilibration thereof.