Doctors or other health care workers usually use three laboratory techniques to diagnose gonorrhea: staining samples directly for the bacterium, detection of bacterial genes or DNA in urine, and growing the bacteria in laboratory cultures. Many doctors prefer to use more than one test to increase the chance of an accurate diagnosis.

The staining test involves placing a smear of the discharge from the penis or the cervix on a slide and staining the smear with a dye. Then the doctor uses a microscope to look for bacteria on the slide. One usually can get the test results while in the office or clinic. This test is quite accurate for men but not for women; only one in two women with gonorrhea have a positive stain.

More often, doctors use urine or cervical swabs for a new test that detects the genes of the bacteria. These tests are as accurate or more so than culturing the bacteria, and many doctors use them.

The culture test involves placing a sample of the discharge onto a culture plate and incubating it up to 2 days to allow the bacteria to grow. The sensitivity of this test depends on the site from which the sample is taken. Cultures of cervical samples detect infection approximately 90 percent of the time. The doctor also can take a culture to detect gonorrhea in the throat. The culture test allows testing for drug-resistant bacteria.