- Although false negative or false positive results are extremely rare, they may occur if the patient has not yet developed antibodies to HIV or if a mistake was made at the laboratory.
- When used in combination with the confirmatory Western blot test, ELISA tests are 99.9% accurate.
Subsequently, How do you read ELISA results? To determine the concentration of each sample, first find the absorbance value on the y-axis and extend a horizontal line to the standard curve. At the point of intersection, extend a vertical line to the x-axis and read the corresponding concentration.
Can an ELISA test be false? False positive results are not uncommon in ELISA for HIV [4], specially in studies of low-risk individuals. In one such study only 13 per cent of ELISA-positive individuals among voluntary blood donors actually had HIV infection [5].
Yet, How accurate is ELISA after 3 months? HIV tests after the 3 month window are more than 99.97% accurate. They work for all types and subtypes of HIV. Very few medical tests have 100% accuracy. There will still be rare cases where someone is HIV positive and not picked up.
Why is ELISA test so sensitive? Why is an ELISA test so sensitive? ELISAs tend to be the most sensitive immunoassays due to the binding characteristics of the antibodies and the amplification or different read-out systems used. Sample volumes can also be adjusted when you have a very low abundant protein.
What is a standard in ELISA?
The ELISA standard curve is prepared by making serial dilutions of standard with known concentration, i.e. from the standard stock solution. The standard range of the assay found in the ELISA protocol should be used as a guideline for the standard curve.
What are the different types of ELISA?
There are four major types of ELISA:
- Direct ELISA (antigen-coated plate; screening antibody)
- Indirect ELISA (antigen-coated plate; screening antigen/antibody)
- Sandwich ELISA (antibody-coated plate; screening antigen)
- Competitive ELISA (screening antibody)
How accurate is ELISA test after 6 weeks?
If you test at 6 weeks after having unprotected (condomless) sex with a new partner, and that test is negative, there is a 99% chance you do not have HIV from that sexual exposure. With any HIV test, you should test again at 3 months to be sure.
