<prompt> The normal time required to culture mycobacterium TB is :4-8 weeks2-3 weeks6-10 weeks21 days  <response>: M. tuberculosis 4-8 weeks is required before growth is detected. New methods have decreased the time required for bacteriologic confirmation of TB to 2-3 weeks. Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page 1350 