Methods to detect and quanitify Mycobacterium leprae(M. leprae)are needed for studies involving the epidemiology, pathogenesis, and chemotherapy of leprosy. Serological assays and skin tests lack the sensitivity and specificity to serve as diagnostic tool for M. leprae infection. The polymerase chain reaction(PCR) based on the selective amplification of an 530-bp frangment of the gene encoding the proline-rich antigen of M. leprae was performed with sections of fixed or frozen biopsy samples from leprosy patients.

This study was done to investigate the applicability of PCR for the detection of low numbers of M. leprae in tissues and peripheral blood.

The PCR was used to amplify a 530-base-pair M. leprae DNA with the thermoxtable Taq DNA polymerase.

The In frozen skin tissues and peripheral blood of leprosy patients. relatively high detection rates of PCR products was achieved by using direct gel analysis as well as Southern blot hybridization.

These results suggest that PCR amplification for the detection of M. leprae may be useful for the epidemiologic study of large papulations as well as coinical astudies on the individual patients.