Varicella zoster IgM
The VZV IgM Enzyme Immunoassay Kit provides materials for the qualitative and semiquantitative determination of IgM-class antibodies to Varicella zoster Virus in human serum or plasma
Varicella-Zoster Virus (human herpes virus 3, HHV-3) belongs to the a-subfamily of herpesviridae. The virus particles measure about 145 nm in diameter. They consist of double stranded DNA, are surrounded by an icosahedral protein capsid and an envelope which contains both host cells and viral components. The virus is usually transmitted in respiratory secretions, and a single serotype causes varicella (Chickenpox), a highly infectious childhood disease, and zoster (shingles), a neurodermic disease; both diseases are found worldwide. Varicella is the acute disease which follows primary contact with the virus, whereas zoster is the response of the partially immune host to a reactivation of the varicella virus present in the body in latent form. Varicella is endemic, most commonly affected are children between 2 and 6 years of age. The course of disease is usually mild and complicated only in immunocompromised children. Rare fatal cases show multiple necrotic lesions in brain, lung (varicella pneumonia), kidneys (hemorrhagic nephritis), spleen, bone marrow, and occasionally in the intestinal tract. The lethality of varicella is below 0.1%. In the infrequent adult infections the disease is more severe, and complications are to be expected in about 5% of all cases. Zoster is of low incidence and appears with increasing frequency and severity with advancing age. Usually the process remains localized, generalization is frequently encountered in a state of immunosuppression. Fatal cases are very rare and nearly always caused by an underlying disease.
The VZV IgM ELISA Kit is a solid phase enzyme-linked immunosorbent assay (ELISA)
Patient samples are diluted with Sample Diluent and additionally incubated with IgG-RF-Sorbent, containing hyperimmune anti-human IgG-class antibody to eliminate competitive inhibition from specific IgG and to remove rheumatoid factors. This pretreatment avoids false negative or false positive results.
Microtiter wells as a solid phase are coated with inactivated Varicella zoster Virus antigen (wild strain isolate). Diluted patient specimens and ready-for-use controls are pipetted into these wells. During incubation Varicella zoster Virus-specific antibodies of positive specimens and controls are bound to the immobilized antigens.
After a washing step to remove unbound sample and control material horseradish peroxidase conjugated anti-human IgM antibodies are dispensed into the wells. During a second incubation this anti-IgM conjugate binds specifically to IgM antibodies resulting in the formation of enzyme-linked immune complexes.
After a second washing step to remove unbound conjugate the immune complexes formed (in case of positive results) are detected by incubation with TMB substrate and development of a blue color. The blue color turns into yellow by stopping the enzymatic indicator reaction with sulfuric acid. The intensity of this color is directly proportional to the amount of Varicella zoster Virus-specific IgM antibody in the patient specimen. Absorbance at 450 nm is read using an ELISA microtiter plate reader.
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