Reasons and Procedure For Conducting a ELISA Lab Test

Submitted on March 27, 2012

The elisa lab test or the enzyme-linked immunosorbent assay is the first test which is done to detect HIV infection. Elisa testing can detect the antibodies to HIV which are present in the blood.

These antibodies appear in the blood between 2 weeks to 6 months, after the original infection. This period, between the infection and the appearance of the HIV antibodies, is referred to as the 'window' period or the seroconversion. During this period, even if a person is infected, elisa tests may not detect any antibodies in the blood. But the person is capable of spreading the disease.

If a person suspects that s/he has been exposed to HIV, but the test de elisa turns out to be negative (that is no HIV antibodies are present), the test should be repeated. They should be done after 6 weeks, then 3 months and finally again after 6 months. This will help to rule out any chances of infection.

If the elisa testing gives a positive result, another HIV test called Western Blot should be done to confirm the infection.

Reasons Why a ELISA Lab Test is Conducted

They are usually recommended for:

  • People who have a high risk factor for getting HIV (job or lifestyle related), or those who are exhibiting certain symptoms of human immunodeficiency virus (HIV) infection.
  • To screen organ donors, blood or blood products, and thus prevent spread of HIV.
  • To screen pregnant women, and babies born to HIV-positive mothers.

Test Kits

Elisa test kits can be bought through mail order or at pharmacies. These home kits come with materials and instructions. They have the advantage of privacy, since the blood sample can be collected at home, sent to the lab for analysis, and the results obtained on the phone using an anonymous code number.


This is done in the same way as other blood tests. An area in the inner elbow is cleaned with antiseptic, and the skin is punctured with a needle. Blood is drawn in a tube and sent to the lab for testing.

There are no risks involved in this test. But you may feel a slight stinging sensation when the needle punctures the skin. There may be a small bruise for a few days.

The results of the test may be affected if you drink too much alcohol, use cortisteroids or have syphilis, leukemia or an autoimmune disease.