Factors affecting the consecutive and simultaneous coupling with bis-diazotized benzidine of protein antigen to sheep red blood cells.

The dynamics of attaching antigen to sheep red blood cells using bis-diazotized benzidine ( BDB ) were studied using purified protein derivative tuberculin as antigen. Factors considered were the concentration of antigen and BDB , temperature, time, and simultaneous or consecutive coupling. Simultaneous coupling at 42 degrees C for 10 min gave the most specific haemagglutination reactions and was simple to carry out.