Latex agglutination test

The latex agglutination test is a laboratory method to check for certain antibodies or antigens in a variety of bodily fluids including saliva, urine, cerebrospinal fluid, or blood.

How the Test is Performed

The test depends on what type of sample is needed.

  • For a urine sample, see urine collection -- clean catch or urine collection (infants).
  • For a blood sample, see venipuncture.
  • For a cerebrospinal fluid sample, see CSF collection.

The sample is sent to a lab, where it is mixed with latex beads coated with a specific antibody or antigen. If the suspected substance is present, the latex beads will clump together (agglutinate).

For example, if your health care provider suspects that your child has strep throat, a throat swab is taken. The sample is mixed with latex beads that are coated with antibodies against the bacteria. If your child has strep throat, the bacteria in the sample will react with the antibodies on the latex particles causing clumping.

Latex agglutination results take about 15 minutes to an hour.

How to Prepare for the Test

Your health care provider may tell you to limit certain foods or medications shortly before the test to ensure accurate test results.

How the Test Will Feel

How the test feels depends on how the sample is collected.

Why the Test is Performed

This test is a quick way to determine the absence or presence of an antigen or antibody. Your health care provider will base any treatment decisions, at least in part, on the results of this test.

Normal Results

Normal values reveal no agglutination.

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

If there is an antigen-antibody match, agglutination will occur.

Risks

Risks depend on how the sample is collected.