Improved surface culturing of Mycobacterium tuberculosis.

In studies on surface components of virulent mycobacteria, there is a continuous need for relatively large quantities of these organisms as produced in surface culture in Roux bottles. Achieving effective surface growth depends upon adequately seeding the surface of the liquid medium. A practice which may well have been employed even by Koch has been the transfer of a pellicle of "veil growth" from a mature surface culture into a fresh flask, and lowering the pellicle gently onto the surface of the liquid medium (H. S. Willis and M. M. Cummings, Diagnostic and Experimental Methods in Tuberculosis, p. 111, Charles C Thomas, Publisher, Springfield, Ill., 1952). The "donor" veil may be obtained according to a method described by H. Zinsser (Microbiology, p. 512, 13th ed., Meredith Publishing Co.,