Evaluate approximately 4,000 to 5000 compounds per year for antimicrobial growth-inhibition activity against Mycobacterium tuberculosis. Improve, standardize, and adopt new assays for determining the activity of compounds against dormant (slowly growing, persistent, or quiescent) M. tuberculosis organisms. Evaluate approximately 1000 selected compounds per year for inhibition of replication of intracellular M. tuberculosis. Evaluate therapeutic agents for efficacy against M. tuberculosis in an infected mammalian cell culture test system.