A test used to detect the presence of an antibody or antigen in a variety of bodily fluids including saliva, urine, cerebrospinal fluid or blood.
How the test is performed
For collection methods, see the specific topics:
- urine (see Urine collection - clean catch for adults and children, and Urine collection (infants) for infants)
- serum (see venipuncture)
- blood cells (see venipuncture)
- CSF (see lumbar puncture)
Depending on the sample under investigation and what your healthcare provider is looking for, either antibody or antigen is attached to latex beads. If the corresponding antigen or antibody is present, the latex beads agglutinate (clump together into visible particles) when mixed with the sample. 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 bacterium. If your child has strep throat, the bacteria in the sample will react with the antibodies on the latex particles causing agglutination. Latex agglutination is quick, and your health care provider should have the results in 15 minutes to an hour.
How to prepare for the test
As with any test, your health care provider may limit certain foods or medications shortly before the test to assure accurate test results.
How the test will feel
How the test feels depends on how the sample is collected. Please see the individual topics for information in this area.
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 intervention for your particular need, at least in part, on the results of this test.
Normal values reveal no agglutination.
What abnormal results mean
If there is an antigen-antibody match, agglutination will occur.
What the risks are
Risks are associated with how the sample is collected. Please see the individual topics for information in this area.
by Sharon M. Smith, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.