The health care provider uses sterile cotton or gauze to clean the opening of the urethra at the tip of the penis. To collect the sample, a cotton swab is then gently inserted about three-fourths inch (2 centimeters) into the urethra and turned. To get a good sample, the test should be done at least 2 hours after urinating.

The sample is sent to a lab. There, it is placed in a special dish (culture). It is then watched to see if bacteria or any other germs grow.

DO NOT urinate for 1 hour before the test. Urinating washes away some of the germs needed for accurate test results.

There is usually some discomfort from swabbing the urethra.

The provider often orders the test when there is a discharge from the urethra or other symptoms of infection. This test can detect sexually transmitted infections (STIs), such as gonorrhea and chlamydia.

A negative culture, or no growth appearing in the culture, is normal.

Abnormal results can be a sign of infection in the genital tract. These infections can include gonorrhea or chlamydia.

Fainting may occur when the swab is introduced into the urethra. This is due to stimulation of the vagus nerve. Other risks include infection or bleeding.

Culture of urethral discharge; Genital exudate culture; Culture - genital discharge or exudate; Urethritis - culture

Babu TM, Urban MA, Augenbraun MH. Urethritis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 107.

Plourde AR, Beavis KG. Specimen collection and handling for diagnosis of infectious diseases. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 66.

Updated by: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.