MedlinePlus Medical Encyclopedia: Urine culture

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Urine culture - clean catch

Contents of this page:
Illustrations Alternative names Definition How the test is performed How to prepare for the test How the test will feel	Why the test is performed Normal Values What abnormal results mean What the risks are Special considerations

Illustrations

Urine sample

Female urinary tract

Male urinary tract

Alternative names Return to top

Urine collection - clean catch; Clean catch urine specimen

Definition Return to top

A clean catch is a method of obtaining a urine sample to be sent for various tests, including urinalysis and urine culture.

How the test is performed Return to top

Collect a "clean-catch" (midstream) urine sample. To obtain a clean-catch sample, men or boys should wipe clean the head of the penis. Women or girls need to wash the area between the lips of the vagina with soapy water and rinse well. As you start to urinate, allow a small amount to fall into the toilet bowl (this clears the urethra of contaminants). Then, in a clean container, catch about 1 to 2 ounces of urine and remove the container from the urine stream. Give the container to the health care provider or assistant.

For an infant:
Thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on your infant. For males, the entire penis can be placed in the bag and the adhesive attached to the skin. For females, the bag is placed over the labia. Place a diaper over the infant (bag and all). Check your baby frequently and remove the bag after the infant has urinated into it. For active infants, this procedure may take a couple of attempts. Lively infants can displace the bag, causing an inability to obtain the specimen. The urine is drained into a container for transport back to the health care provider.

How to prepare for the test Return to top

A specimen container and instructions on cleansing and collection will be provided. If the collection is being taken from an infant, a couple of extra collection bags may be necessary.

How the test will feel Return to top

Rarely, infants may have a local skin reaction to the tape used with the collection bags.

Why the test is performed Return to top

The clean-catch method is used to avoid contaminating the urine sample with bacteria that are normally present in the urethra and appear in a voided urine sample. It is used for a routine urinalysis, a urine culture, or other urine tests that require uncontaminated urine for accurate results.

Normal Values Return to top

Normal values will depend on the specific test ordered, for example, urinalysis or urine culture.

What abnormal results mean Return to top

If the urine sample was sent for urinalysis, abnormal results may indicate the presence of white blood cells, red blood cells, or excessive amounts of protein.

If the urine sample was sent for urine culture, abnormal results may indicate excessive growth of bacteria a urinary tract infection or bladder infection.

What the risks are Return to top

No risks have been noted in collecting a clean catch urine sample.

Special considerations Return to top

This is a common method used to collect urine. A false negative urine culture may result from recent antibiotic use.

Update Date: 8/11/2003

Updated by: Kenneth Wener, M.D., Department of Infectious Diseases, Beth Israel Deaconess Medical Center, Boston, MA. Review provided by VeriMed Healthcare Network.

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