Particulate antigens were made from the Texas and Jo turkey ornithosis agents and an ornithosis agent isolated from a whitewinged dove. The McCoy cell line was used to grow these chlamy. diae. Different methods for harvesting, treating, and preserving the antigens were tried in an attempt to determine the most satisfactory method of antigen preparation. Antigens were used in slide microagglutination and tube agglutination with preinoculation and postinoculation serums from turkeys infected with the Texas or Jo turkey ornithosis agent. Several different buffered solutions of various pH values and with different ionic strengths were used in the serologic tests in an attempt to find the most desirable conditions for performing such tests.