To obtain an anal culture, insert a sterile, cotton-tipped applicator about an inch (2 cm) into the anal canal.
Rotate the cotton-tipped applicator, sampling the anal crypts.
Remove the applicator, and send the specimen in media appropriate for the organism you are seeking:
Chocolate agar plates for gonorrhea (or other suitable culture media)
Blood agar plates for strep (or other suitable culture media)
If the applicator becomes grossly contaminated with stool, it is better to discard it and obtain another specimen.
Source: Operational Medicine 2001, Health Care in Military Settings, NAVMED P-5139, May 1, 2001, Bureau of Medicine and Surgery, Department of the Navy, 2300 E Street NW, Washington DC, 20372-5300, USA