History and characteristics of isolates maintained at the leprosy research center.

The origin, history, sensitivity to anti-leprosy drugs and genotypic characteristics for 27 strains maintained at the Leprosy Research Center in Tokyo are described. Strains are isolated and passaged in nude mouse footpads, and frozen bacillary suspensions with different generations are also maintained. The Leprosy Research Center provides bacillary materials as experimental resources at researchers' request.