Formalinized Chlamydia trachomatis organisms as antigen in the micro-immunofluorescence test

Chlamydia trachomatis organisms grown in HeLa 229 cell cultures were purified and formalinized for use in the micro-immunofluorescence test. As test antigens, they were stable when stored unfrozen at 4 degrees C for a long period of time without loss of type specificity and sensitivity.