RUB IgM
Enzyme ImmunoAssay (ELISA) for the determination of IgM antibodies to Rubella Virus in human plasma and sera with the "capture" system. The devise is intended for the follow-up of Rubella Virus infected patients and for the monitoring of risk of neonatal defects due to Rubella Virus infection during pregnancy.
Rubella is a small spherical enveloped virus, 55-60nm in diameter, and is the only member of the genus Rubivirus of the family Togaviridiae.
The virus contains a single positive stranded 42s RNA molecule and only one serotype is known. The virus encodes for at least three envelope glycoproteins, E1, E2a, E2b; a nucleocapsidassociated protein, C; and two nonstructural proteins. The detection of Rubella-specific IgG and IgM antibodies is very important for the serological diagnosis of both congenital and primary postnatal rubella infections as they can lead to severe birth defects.
The absence of Rubella-specific IgG antibodies in sera, characteristically of long-term duration after primary infections, in presence of virus-specific IgM, is indicative for the risk of defects in newborn infants.
Highly specific Rubella IgM assays, based on the IgM-capture system, are now able to provide the clinician with a helpful and reliable test for the monitoring of these risks in pregnancy.
The assay is based on the principle of “IgM capture” where IgM class antibodies in the sample are first captured by the solid phase coated with anti hIgM antibody.
After washing out all the other components of the sample and in particular IgG antibodies, the specific IgM captured on the solid phase are detected by the addition of a purified preparation of inactivated Rubella Virus, labeled with a specific monoclonal antibody conjugated with peroxidase (HRP).
After incubation, microwells are washed to remove unbound conjugate and then the chromogen/substrate is added.
In the presence of bound conjugate the colorless substrate is hydrolyzed to a colored end-product, whose optical density may be detected and is proportional to the amount of IgM antibodies to Rubella Virus present in the sample.
A system is described how to control whether the positivity shown by a sample is true or not (Confirmation Test), helpful for the clinician to make a correct interpretation of results.
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