used for the isolation of gonococci (Neisseria gonorrheae) from specimens containing a mixed flora of bacteria and/or fungi e.g. urogenital specimen. is a GC agar base containing vancomycin, colistin, nystatin, and trimethoprim lactate (VCNT). Selective isolation of Neisseria gonorrhoeae is achieved with suppression of most other gram-negative diplococci, gram-negative bacilli, gram-positive organisms, and yeast.