What is ELISA for p24 antigen?
Most commercial HIV-1 p24 assays employ a standard ELISA format for the capture and detection of p24 antigen. A crucial disadvantage shared by these commercially available ELISAs is that they are capable of detecting only 5–25 pg/mL of HIV-1 p24 antigen in the absence of signal amplification [3].
How does p24 ELISA work?
How does a p24 ELISA work? The virus in your supernatant is first lysed in the supplied buffer system to release p24. The sample is then applied to a 96-well microtitration plate (made up of 12 separable 8-well strips), in which the wells are pre-coated with murine anti-p24 capture antibody.
What is the normal range of p24 antigen?
Nine (11.25%) samples, which were tested negative for RNA, were found to be positive for p24 antigen. The range of p24 quantitation in these samples was 2.36 to 3.25 log10 fg/ml.
What is p24 antigen test?
An antigen test checks your blood for an HIV antigen, called p24. When you’re first infected with HIV, and before your body has a chance to make antibodies to the virus, your blood has a high level of p24. The p24 antigen test is accurate 11 days to 1 month after getting infected.
How reliable is p24 antigen test?
That said, the rapid HIV Antigen/Antibody combination test is extremely accurate, with the manufacturer claiming 100% sensitivity and 99.91% specificity.
Can p24 be false positive?
The likelihood of a false positive HIV test increases as the prevalence of HIV decreases and other potential explanations for the presence of p24 antigen become as prevalent as HIV. Often, patients with a false positive laboratory signature do not have other serum evidence of HIV infection.
How long is p24 antigen detectable?
In these tests the antigen being tested is a major HIV protein called p24. p24 (short for protein 24) is produced 2–3 weeks after infection and before antibodies are produced. p24 levels are only detectable for the next 1–2 months. However, by the time the p24 levels have dropped antibodies will be present.
How accurate is the p24 antigen test?
Antibody/antigen test.
Newer antigen/antibody combination tests (you might hear them called “fourth generation” tests) can find HIV in 99% of people who are tested within 13-42 days of exposure. This test has become the standard HIV blood test in most labs.
How accurate is ELISA test after 4 weeks?
The test highly accurate after 4 weeks, and almost 100% accurate after 8 weeks. If you have had unprotected sex or shared injecting equipment in the last 6-8 weeks, we recommend you take another test in 6 weeks to be sure of your status.