Comparative studies on two antigens (F4 and TM) extracted from leptospires

F4 and TM antigens extracted from Leptospira interrogans serovars pomona, icterohaemorrhagiae, and copenhageni were compared by immunodiffusion, by hemagglutination inhibition, and by selective absorption of antisera. These data, together with previous information on the serological specificities of the two antigen preparations, suggest that F4 and TM are different antigens.