A method for preparing microbeads for use in an assay for determining the presence of antibodies to human immunodeficiency virus in a sample

摘要

A method for preparing microbeads for use in an assay for determining the presence of anti bodies to human immunodeficiency virus in a sample HIV antigen coated microbeads for use in an assay for determining the presence of antibodies to HIV in blood or other sample comprises initially acylating a selected HIV antigen in a citraconic anhydride solution for coating onto polystyrene microspheres. The microspheres are precoated with bovine serum albumin and then coated with the acylated HIV antigen and incubated fro between 18 and 24 hours at room temperature. The HIV antigen coated microspheres are then deacylated by washing in a citric acid buffer of pH of 4.8, and incubating at 35 degrees C to 39 degrees C for 18 to 24 hours. The microspheres are then washed in a Tris buffer, and are suspended in a 1 percent bovine serum albumin Tris polyethylene glycol solution at a concentration of approximately 1 percent, and the suspension is allowed to equilibrate for 6 to 8 days at the temperature in the range of 2 degrees C to 8 degrees C. A sample to be tested is mixed with the suspension, and an agglomeration of the microspheres is indicative of a positive sample.