Figure 3. Description and costs of the direct Griess method in Peru. A) Pan-susceptible Mycobacterium tuberculosis isolate. B) M. tuberculosis isolate resistant to isoniazid (INH) and rifampin (RIF). The left (control) tube in panel A and all tubes in panel B indicate mycobacterial growth. The costs of the test are US $5.30 per sample, including personnel, materials (items that can be reused), and supplies (reagents and consumable items), and US $4.80 per sample, including materials and supplies.