Serological characteristics of the Leptospira serogroup Pomona. II. Changes in the agglutination and absorption properties of the reference strains after formalin- and heat-inactivation.

After formalin or heat-inactivation for 30 minutes at 56 degrees C, the absorption properties of some Pomona serogroup strains diminish, which indicates that they have thermolabile (Pomona, CZ 299U and LT 796) or formalin-labile (Pomona and 5621) minor antigenic factors. The agglutination properties of the various strains change differently after inactivation though not in parallel with the absorption properties.