One-step staining of Neisseria gonorrhoeae in urethral discharge by methyl green-pyronin.

Methyl green-pyronin (MGP) was used in a one-step procedure to stain smears of urethral discharge from 169 men. Duplicate smears were stained by Gram's method and discharge was cultured for Neisseria gonorrhoeae. The organisms were isolated from 67 specimens and intracellular diplococci were seen in 74 smears after Gram staining and in 77 after staining by MGP. Furthermore, more extracellular and intracellular diplococci were seen in smears stained by MGP than by Gram's method and the proportion of polymorphonuclear leucocytes found to contain the organisms was greater after staining with MGP. Staining with MGP is simple, rapid, inexpensive, and easily automated.