Formalin is widely used to fix histological preparations, and as preservatives, in embalming solutions. It is an age-long practice in medical laboratories. It is generally accepted that the risk of contracting tuberculosis is relatively high among Medical Laboratory workers and Pathologists. It is an assumption that once tissue is fixed in formalin, the risk for transmission and subsequent infection of Mycobacteria is greatly reduced, if not altogether eliminated. Cadavers remain a practical teaching tool for Anatomists and Medical educators teaching gross anatomy. Infectious pathogens in cadavers that present particular risks include Mycobacterium tuberculosis, Hepatitis B and C, the AIDS virus HIV, and Prions that cause transmissible spongiform encephalopathies. Recent studies have however, suggested that formalin does not effectively inactivate Mycobacterium tuberculosis in formalin-fixed tissue. In this study we tried to test the inactivation ability of (a) 10% formalin fixation and (b) Treatment of tissue with 75% ethanol 2 hours prior to 10% formalin fixation. Multiple Drug Resistant (MDR) and Multiple Drugs Susceptible (MDS) strains of Mycobacterium tuberculosis were employed.
Last date updated on August, 2020