Abstract: Objective To set up and assess Alamar blue and MTT assays for determining the MIC of the anti-tuberculosis drugs to Mycobacterium tuberculosis.Methods MIC of 12 anti-tuberculosis agents to Mycobacterium tuberculosis H₃₇R_V were determined by Alamar Blue assays and MTT,and compared to the conventional two folds dilutions.Results For Alamar blue assays and MTT,the time for obtaining Results were 6 days and 8 days,respectively.MICs determined by MTT or Alamar blue assay were highly correlated with those determined in the two folds dilutions.Conclusion Alamar blue and MTT assays are sensitive,rapid,inexpensive,and promising new alternative Methods for performing rapid high-throughout screening of compounds against Mycobacterium tuberculosis.

Key words: Antitubercular agents, Cell division, Tetrazolium salts, Colorimetry