![]() ![]() The test is simple and can be performed in small setup labs as only a rotary shaker is required to complete the test. The presence of only the control band is interpreted as HIV Negative. In that case, the sample is interpreted as INDETERMINATE for HIV. Suppose the band does not meet the positive criteria, i.e., either presence of 1 envelope band and GAG &/or POL band or only GAG OR POL band. Envelope (gp120,gp160,gp41), GAG (p17,p24&p55) and POL(p51, p31 & p66).įor a sample to be HIV Positive, a Control band and at least 2 HIV envelope bands along with any 1 GAG or 1 POL band shall be present on the strip. The results are interpreted as Negative, Positive, or Indeterminate based on the presence of bands on the strip at the corresponding HIV Antigen. The test is run on strips blotted with HIV viral antigens, and the blue color bands appear on the strip after the test is completed due to the use of Alkaline phosphatase enzyme and BCIP –NBT substrate in the process. HIV Testing is performed using screening test Rapid /ELISA and samples found reactive in these tests are confirmed for their status by Western blot. The Western Blot test is the confirmatory test to detect antibodies to HIV (Human immunodeficiency virus), the causative agent of AIDS (Acquired Immunodeficiency Syndrome). Western blotting is used for the confirmatory medical diagnosis of various infectious diseases and, to name a few, HIV, bovine spongiform encephalopathy (BSE), hepatitis C (HCV), syphilis, and autoimmune disorders.Īs per WHO guidelines, this technique has been widely used as a more specific & supplemental assay on samples found initially reactive using ELISA and other screening tests for HIV. ![]() Western blot is a technique used for protein detection from a mixture of proteins and has its application in immunology, molecular biology, biochemistry, and cell biology fields. Significance Of Malaria Antigens Over Antibodies.When objective and nonspecific systemic symptoms of Lyme disease are absent, or when systemic symptoms have not persisted for a sustained period, serologic testing is not recommended. When objective signs of Lyme disease are absent, but unexplained nonspecific systemic symptoms have persisted for a long time (i.e., several weeks) in an individual from a highly or moderately endemic area for Lyme disease, two-step testing should be considered. Samples drawn within four weeks of disease onset should be tested for immunoglobulin M and immunoglobulin G, and samples drawn four weeks or more after disease onset should be tested for immunoglobulin G only. When pretest probability is moderate (e.g., a patient from a moderately endemic area with objective clinical findings), laboratory testing should be performed by means of the two- step approach. Lyme disease may be diagnosed without serologic testing in a patient from a highly endemic area with objective clinical findings. Physicians should assess the pretest probability of a patient with suspected Lyme disease on the basis of clinical signs and symptoms and the likelihood of exposure. When unexplained non-specific systemic symptoms such as myalgia, fatigue, and paresthesias have persisted for a long time in a person from an endemic area, serologic testing should be performed with the complete two-step approach described above. Patients who show no objective signs of Lyme disease have a low probability of the disease, and serologic testing in this group should be kept to a minimum because of the high risk of false-positive results. Samples drawn from patients within four weeks of disease onset are tested by Western blot technique for both immunoglobulin M and immunoglobulin G antibodies samples drawn more than four weeks after disease onset are tested for immunoglobulin G only. When the pretest probability is moderate (e.g., in a patient from a highly or moderately endemic area who has advanced manifestations of Lyme disease), serologic testing should be performed with the complete two-step approach in which a positive or equivocal serology is followed by a more specific Western blot test. These patients do not require serologic testing, although it may be considered according to patient preference. In patients from endemic areas, Lyme disease may be diagnosed on clinical grounds alone in the presence of erythema migrans. The approach to diagnosing Lyme disease varies depending on the probability of disease (based on endemicity and clinical findings) and the stage at which the disease may be. The use of serologic testing and its value in the diagnosis of Lyme disease remain confusing and controversial for physicians, especially concerning persons who are at low risk for the disease. ![]()
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