Effect of freezing Mycobacterium leprae in tissues.

The effects of freezing tissues from M. leprae-infected armadillos as well as biopsy specimens from leprosy patients have been studied. No loss of viability of M. leprae was observed using mouse foot pad technique. Similarly, using bioluminescent determinations of bacterial ATP, it was shown that these bacilli retain all their metabolic activity during such freezing and thawing process. The practical implications of these findings have been discussed.