This slant is recommended for cultivation of Mycobacterium tuberculosis and for resistance testing. Lowenstein Jensen Medium Base w/o Starch is recommended for drug resistance testing of Mycobacteria as recommended by WHO. Penicillin and nalidixic acid (FD053) along with malachite green prevents growth of the majority of contaminants. RNA (in FD053) acts as stimulant and helps to increase the isolation rate of Mycobacteria. D-Cycloserine (30 µg/ml) is the antibiotic used for resistance testing.