Immunoassay using /sup 125/I- or enzyme-labeled protein A and antigen-coated tubes
Antigen-coated plastic tubes were used with /sup 125/I- or enzyme-labeled stapylococcal protein A in a general immunoassay method for antigens and haptens. Protein A reacts with immunoglobulin G(IgG) regardless of antibody specificity at sites distal to the antigen combining site and does not inhibit the immune reaction. It therefore serves as a general tracer and its use eliminates the need to purify and to label individual components for each assay. Macromolecular antigens were bound to polystyrene or polypropylene tubes by direct passive absorption. Haptens with free carboxyl groups were bound covalently to poly-L-lysine and these conjugates passively absorbed to the tube surface. Optimal assay conditions were established for the quantitative determination of immunoglobulins and the folate derivatives, methotrexate and 5-methyltetrahydrofolate, using /sup 125/I-labeled protein A or protein A labeled with alkaline phosphatase. The method has been used to estimate levels of IgG, IgA, Igm, and IgE in serum in volumes up to 1 ml.
- Research Organization:
- National Cancer Inst., Bethesda, MD
- OSTI ID:
- 6097109
- Journal Information:
- Anal. Biochem.; (United States), Journal Name: Anal. Biochem.; (United States) Vol. 116:2; ISSN ANBCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
ALKALINE PHOSPHATASE
ANTIGENS
ANTIMETABOLITES
BACTERIA
BETA DECAY RADIOISOTOPES
CHEMICAL BONDS
CHEMICAL REACTIONS
CHEMISORPTION
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
ESTERASES
GLOBULINS
HYDROLASES
IMMUNOGLOBULINS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
MATERIALS
METHOTREXATE
MICROORGANISMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PETROCHEMICALS
PETROLEUM PRODUCTS
PHOSPHATASES
PLASTICS
PROTEINS
RADIOASSAY
RADIOIMMUNOASSAY
RADIOISOTOPES
SEPARATION PROCESSES
SORPTION
STAPHYLOCOCCUS
SYNTHETIC MATERIALS
TRACER TECHNIQUES