Solid phase radioimmunoassay for quantitation of antigen-specific IgG in human sera with /sup 125/I-protein A from Staphylococcus aureus
Radiolabeled protein A from Staphylococcus aureus (Staph A) has been used to develop a solid phase, noncompetitive radioimmunoassay for quantitation of specific IgG antibody. The assay involves two incubations: First, agarose-insolubilized antigen is mixed with serum samples for 1 to 4 h during which specific antibody is bound; second, after a washing procedure, the solid phase immune complexes are incubated for 4 to 18 h with /sup 125/I-Staph A, during which the radiolabeled detection protein binds to the insolubilized specific IgG antibody. In a comparative study of the IgG antiphospholipase A antibody content of 23 human sera drawn from honeybee venom-sensitive patients, results of the Staph A assay correlated highly (r = 0.981, p < 0.001, N = 23) with those obtained from a liquid phase, competitive radioimmunoprecipitation (double antibody) assay. The two assays demonstrated comparable precision, sensitivity, and reproducibility. In contrast, the use of /sup 125/I-Staph A in the solid phase radioimmunoassay was superior to /sup 125/I rabbit anti-human IgG because of lower negative serum (blank) values, shorter time required to reach equilibrium binding, and greater precision and reproducibility. In principle, the /sup 125/ Staph A assay may be applied to IgG quantitation for crude allergen extracts as well as purified antigens. Furthermore, the sera of a number of mammalian species may be studied without further modification.
- Research Organization:
- Johns Hopkins Univ., Baltimore, MD
- OSTI ID:
- 5290944
- Journal Information:
- J. Immunol.; (United States), Vol. 122:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
IMMUNOGLOBULINS
RADIOIMMUNOASSAY
ANTIBODIES
BLOOD SERUM
IODINE 125
MAN
PROTEINS
STAPHYLOCOCCUS
ANIMALS
BACTERIA
BETA DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
GLOBULINS
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MICROORGANISMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PRIMATES
RADIOASSAY
RADIOISOTOPES
TRACER TECHNIQUES
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics