HUMAN IgG SUBCLASS KITS: ELISA METHODOLOGY
Human IgG subclasses ELISA kit
FOR IN VITRO DIAGNOSTIC USE
CAT# RDI-M1551clb PRICE: $600.00/kit
Introduction
Human IgG consists of four subclasses, which show more than 95% homology in the amino acid sequence of the C-domains of their heavy chains. The IgG subclasses show differences in effector functions like antigen recognition, complement activation and cell surface Fc receptor binding. Antibodies against viral capsid proteins were found to belong predominantly to the IgG1 and IgG3 subclasses, whereas IgG2 is the predominant subclass in immune responses against polysaccharides. The IgG4 subclass,although representing a minor fraction in the total serum IgG, has received attention because it is highly responsive to repeated challenges with environmental antigens. The interest in the quantification of human IgG subclasses is supported by a recommendation from a WHO/IUIS working group which states: "Measurement of total levels of IgG subclasses is essential in patients with increased susceptibility to bacterial infections when the total IgG level is within or slightly below the normal range". Recently Shield et al showed that also hypergammaglobulinaemia does not exclude the presence of a IgG subclass deficiency.
The concentrations of IgG subclasses in serum of children varied widely with age. Infants and young children have lower subclass concentrations than adolescents and adults. IgG1 and IgG3 levels rise more rapidly with age than IgG2 and IgG4 concentrations. To determine an IgG subclass deficiency, it is essential to have reliable reference ranges for the individual IgG subclasses.
This IgG subclasses kit is intended for reproducible,sensitive and specific (high correlation to radial immunodiffusion technique) measurement of human IgG subclasses in serum and other biological fluids.
Contents
-precoated microtiterplate (6 strips,48 wells, for each IgG subclass)
-HRP-conjugated anti human IgG antibody
-standards and controls
-concentrated wash-,dilution-,and substrate-buffers.
-reference values for human IgG subclasses
Characteristics
IgG1 IgG2 IgG3 IgG4
-sensitivity (ng/ml) 5 19 2.6 3.5
-correlation with RID(%) 92 86 95 98
-intra-assay variation(%) 8.4 9.3 10 5
-total assay incubation time 2.5 hours.
Applications
-Deficiencies of IgG subclass concentrations are an indication of a distrubed immune response.
-The association of selective IgG2 and/or IgG3 subclass defici ency with increased susceptibility to viral or bacterial infections is amply documented.
-Abnormalities in IgG subclass concentrations have been observed in patients with allergy, autoimmune diseases,neurological disorders, dialysis and during HIV-infections.
References
-2nd IUIS/WHO report (1988) Clin.Exp.Immunol. 74:494
-Hamilton,R.C. (1987) Clin.Chem. 33: 1707
-Jefferis,R. et al (1990) Clin.Exp. Immunol. 81: 357
-Shackelford,P.G. et al (1990) J.Pediatric. 116: 529
-Shakib,F.(Ed) Monograph in Allergy 19 (1986) Karger A.G.
-Shakib,F.(Ed) The human IgG subclass (1990) Pergamon Press
-Shield,J.P.H. et al (1992) The Lancet 340: 448
-Vlug.A. et al (1989) Eur.Clin.Lab. 8: 26
Assay procedure (inquire for full actual protocol)
- Bring all reagents to room temperature
-Add 100ul of diluted standards,controls and samples and incubate ( 1 hour 37'C)
-Incubate with 100ul substrate solution (30 minutes,room temperature, in the dark)
-Read absorbance at 414 nm