EBV-VCA IgA Ab ELISA Kit

INTENDED USE

Enzyme immunoassay for the detection of IgA antibody to the viral capsid antigen (VCA) of Epstein-Barr Virus (EBV) .

INTRODUCTION

Epstein-Barr virus, frequently referred to as EBV, is a member of the herpes virus family and one of the most common human viruses. The virus occurs worldwide, and most people become infected with EBV sometime during their lives. In developed countries, 80 - 90% of the adult population have been infected by the virus. EBV is associated with several diseases state where it may act as the direct agent or as one of several cofactors. These diseases include: Infectious Mononucleosis(IM), Nasopharyngeal carcinoma(NPC), Burkitt's lymphoma(BL), Lymph proliferative disease and lymphoma in the immunosuppressed, X-linked lymph proliferative syndrome, Chronic infectious mononucleosis, Oral leukoplakia in AIDS patients, and Chronic interstitial pneumonitis in AIDS patients. EB virus enters the body through the mouth and establishes a productive infection in the pharyngeal epithelial cells. B-cells become infected and are disseminated throughout the body via the bloodstream. During acute primary infection, IgA, IgM and IgG to VCA as well as IgG to EA(D) and MA are induced. When infection with EBV occurs during adolescence or young adulthood, it causes infectious mononucleosis 35% to 50% of the time. NPC is a genetically restricted tumour, being most common in the Southern Chinese.100% of sera from undifferentiated NPC patients have high-titre antibodies to EB-viral antigens. As in BL, antibodies against VCA are at a 10 times geometric mean titre. IgG and IgA levels against EA (D) and VCA rise as the disease progress and may be used for screening and monitoring purposes. VCA and EA (D) IgA are also uniquely found in the saliva of NPC patients. This is an enzyme linked immunosorbent assay for the detection of EBV-VCA IgA antibodies in Human serum or plasma and is indicated as a screening test for serum or plasma.

Test principle

Sandwich principle.

The EBV-VCA IgA Ab ELISA Kit utilizes a detection system where microplate wells are coated with recombinant antigen corresponding to a highly antigenic segment EBV-VCA. Serum or plasma specimens, controls are added to the wells. During incubation, IgA antibodies specific for EBV-VCA present in the specimen will bind to the recombinant antigen fixed onto the microplate wells. The wells are washed to remove unbound materials, and anti-human IgA peroxidase conjugate will bind to the antigen-antibody complex and excess unbound enzyme conjugates are again removed by washing. The enzyme substrate, tetramethylbenzidine (TMB), is added upon incubation the substrate will be hydrolyzed by the bound enzyme and a blue or blue-green colour develops in wells containing EBV-VCA IgA antibodies. The enzyme reaction is stopped by the addition of sulphuric acid. The intensity of colour developed is read spectrophotometrically at 450nm (450 nm/630 nm) and is proportional to the amount of antibodies present in the specimen.