Antigenic relationships among mycobacterial species studied by modified-rocket and crossed immunoelectrophoresis.

The complexity of antigens from various species of mycobacteria was explored with use of variations in the techniques of fused-rocket immunoelectrophoresis (IEP) and two-dimensional IEP. Resolution and formation of lines of identity depended on shape and arrangement of antigen wells, concentration of reagents, and procedure for electrophoresis. Rocket IEP of a sonicate into heterologous antiserum in one dimension followed by IEP into homologous antiserum in a second dimension permitted ready identification of heterologous reactions, with direct identity to homologous precipitin bands. Variations in procedures provided versatility that permitted comparison of antigens of unknown or different species, expression of relatedness, comparison of different antisera, and progress of purification or fractionation.