Endocervical gram stain is a method of identifying bacteria on tissue from the cervix using a special series of stains.
Gram stain of cervix
How the test is performed
This test requires a sample of tissue from the lining of the cervical canal (the opening to the uterus).
You lie on your back with your feet in stirrups. The health care provider with insert an instrument called a speculum into the vagina. This instrument is used during regular female pelvic exams. It is used to stretch open the vagina in order to better view certain pelvic structures.
After the cervix is cleaned, a dry, sterile swab is inserted through the speculum and to the cervical canal and gently turned. It may be left in place for a few seconds to absorb as many germs as possible.
The swab is removed and sent to a laboratory, where it will be smeared on a slide. A series of stains called a gram stain is applied to the sample. A laboratory technician looks at the stained smear under the microscope for the presence of bacteria. The color, size, and shape of the cells help identify the type of bacteria.
How to prepare for the test
Do not douche for 24 hours before the procedure.
How the test will feel
You may feel minor discomfort during specimen collection. This procedure feels very much like a routine Pap smear.
Why the test is performed
The test is used to detect and identify abnormal bacteria in the area of the cervix. If you develop signs of an infection or suspect that you have a sexually transmitted disease (such as gonorrhea), this test can help confirm the diagnosis, and identify the organism that is causing the infection.
A normal result means no abnormal bacteria are seen in the sample.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
The test may also be performed for gonococcal arthritis, to determine the site of the initial infection.
What the risks are
There is virtually no risk.
If you have gonorrhea or another sexually transmitted infection, it is very important that all of your sexual partners also receive treatment, even if they have no symptoms.
McCormack WM. Urethritis. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 106.
Cohen MS. Approach to the patient with a sexually transmitted disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 293.
Workowski KA, Berman S; Centers for Disease Control and Prevention (CDC). Sexually transmitted diseases treatment guidelines, 2010. MMWR Recomm Rep. 2010 Dec 17;59(RR-12):1-110.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.