DNA isolated from Mycobacterium leprae: genome size, base ratio, and homology with other related bacteria as determined by optical DNA-DNA reassociation.

DNA derived from Mycobacterium leprae (grown in armadillos) was isolated, purified, and analyzed spectrophotometrically. The genome size and the guanine-plus-cytosine content of M. leprae were 1.3 x 10(9) and 55.8%, respectively. Among selected strains of mycobacterial, nocardial, and corynebacterial species, Corynebacterium sp. 2628 LB, isolated from a human leprosy patient, showed the highest DNA homology with M. leprae. Of the DNAs derived from mycobacteria, those of M. tuberculosis and M. scrofulaceum showed a comparatively high reassociation with the DNMA of M. liprae.