How does the Monospot test work?

Monospot test (heterophil test). This quick screening test detects a type of antibody (heterophil antibody) that forms during certain infections. A sample of blood is placed on a microscope slide and mixed with other substances. Monospot testing can usually detect antibodies 2 to 9 weeks after a person is infected.Click to see full answer. In this way, how accurate is the Monospot test?The latex agglutination assay, which is the basis of the Monospot test using horse RBCs, is highly specific. Sensitivity is 85%, and specificity is 100%. The heterophile antibody test (eg, the Monospot test) results may be negative early in the course of EBV infectious mononucleosis.Also Know, how long before mono test is positive? It is initially positive in the second or third week of infection. It usually wanes by 2–4 weeks and may not develop at all in young children. Next is IgG to VCA. It is initially positive in second to fourth week of infection and detectable for life. Furthermore, what does the Monospot test detect? A mononucleosis spot (or Monospot) test is a blood test used to determine whether or not you are infected with the Epstein-Barr virus, which is the organism that causes infectious mononucleosis.Can you test negative for mono but still have it?If the first test does not indicate mono but you still have symptoms, the test may be repeated. Although the symptoms of these infections and diseases are similar to mono, the monospot test usually will be negative. Having a weakened immune system.