While the diagnosis of autoimmune diseases requires an accurate determination of antibodies to the autologous or environmental antigens, the test can produce a false positive result when an unrelated antibody reacts with an antigen. The two types of false positive reactions can be caused by a number of factors, including technical error, testing during a window period, and decreased host immunoglobulin production (as in AIDS or common variable immunodeficiency).
A range of factors can contribute to a false positive result, ranging from inadequate dilution of test sera to the omission of non-coated control wells. These factors can influence the accuracy of ELISA tests, and a solution known as ChonBlock is one way to eliminate them. ChonBlock prevents these confounding factors by eliminating the possibility of cross-reactivity between antibodies and antigens.
Conventional ELISA buffer systems are insufficient for assaying antibodies in human sera because they have poor blocking effects on non-specific reactions. A secondary antibody may also cause a false positive reaction, a result of the hydrophobic binding of immunoglobulin components on the surface of the plate. Commercially prepared ELISA plates generally do not include control wells. In addition to false positive reactions, these non-specific reactions can lead to uncertain conclusions.
Another solution for reducing false positives is the HerdChek X3 PRRS Elisa. It offers improved sensitivity and specificity, reducing the risk of false positives by 75-90%. Elisa also offers improved reproducibility, as it detects antibodies to either European or North American strains. The HerdChek X3 ELISA reduces false positives by 90%.
Another solution to the problem of ELISA false positives is to test specimens of two or three anopheline species for Plasmodium vivax. This strategy is effective for testing malariae and falciparum, and it can confirm PCR results in many cases. This is particularly important if the test is used in areas that are difficult to diagnose. But if it fails to detect the targeted parasites, it could lead to false positives.
False negatives can also occur when ELISA tests are performed for HIV infection. The test can be false positive if the patient has no antibodies to the virus, or it may be because the laboratory makes an error. False positive results may require repeating the test in a few weeks, or a more sensitive test is necessary. If you think your test is inaccurate, don't worry. ELISA tests are 99.9% accurate when used in conjunction with Western blot tests, so you can rest assured that you are in safe hands. A clean ELISA plate could avoid errors, and an ELISA washer is available for this.