The Diagnostic Automation Measles IgG ELISA kit is intended for the detection and quantitative determination of IgG antibody to Measles (Rubeola) virus in human sera. Individual serum specimens may be used for the determination of immune status. Paired sera, acute and convalescent, may be used to demonstrate seroconversion or a significant rise in antibody as an aid in the diagnosis of recent or current infection.
Since the introduction of a measles virus vaccine, the U.S. has mounted an effective immunization program which has essentially eliminated measles as a major childhood disease. However, as a result of vaccine failure or the failure to be vaccinated, a recent and persistent shift in the susceptible population towards young adults has been recorded. In the case of measles, severity of illness and mortality rates are highest among adults. Thus, serology has become increasingly important as a tool for determining the immune status of the young adult population entering college or the military. In addition, the linkage between measles infection and premature delivery or spontaneous abortion supports screening pregnant mothers for susceptibility. Several diseases in addition to Measles have been associated but not causally linked to measles virus. This list includes subacute sclerosing panencephalitis (SSPE), systemic lupus erythematosus (SLE) and multiple sclerosis (MS). Patients with SSPE, a chronic degenerative neurologic disease, have documented high levels of antibody to measles virus. However, for SLE and MS there is less pronounced but statistically significant elevation in antibody levels. The significance or role of measles virus infection in these disease states is unknown at the present time. Since the presence of circulating IgG antibody to measles virus is indicative of previous infection or vaccination, screening the young adult population about to enter college or the military, pregnant women, and other individuals at risk, for seropositivity, is a valuable tool for determining their immune status.
The immune response to infection or vaccination with measles virus is rapid and characteristic. Measles specific IgM and IgG begin to appear in the circulation simultaneously. The IgM response is in 1 to 3 months, while IgG response is sustained, meaning the test for measles will determine life-long immunity.
Purified Measles antigen is coated on the surface of microwells. Diluted patient serum is added to wells, and the Measles IgG specific antibody, if present, binds to the antigen. All unbound materials are washed away. After adding enzyme conjugate, it binds to the antibody-antigen complex. Excess enzyme conjugate is washed off, and TMB Chromogenic Substrate is added. The enzyme conjugate catalytic reaction is stopped at a specific time. The intensity of the color generated is proportional to the amount of IgG specific antibody in the sample. The results are read by a microwell reader compared in a parallel manner with calibrator and controls.
DAI Measles IgG ELISA This kit is designed to measure IgG antibody in patient samples. Positive results in neonates must be interpreted with caution, since maternal IgG is transferred passively from the mother to the fetus before birth. IgM assays are generally more useful indicators of infection in children below 6 months of age.