Biomaterial Database

Use of protein A--containing Staphylococcus aureus as an immunoadsorbent in radioimmunoassays to separate antibody-bound from free antigen. 1979

M A Frohman, and L A Frohman, and M B Goldman, and J N Goldman

Heat killed, formalinized Cowan I strain Staphylococcus aureus (PASA) was examined for its utility as a solid-phase immunoadsorbent in various RIA procedures. Specific antibody could be adsorbed to PASA and then reacted with radiolabeled and unlabeled hormone, or alternatively, PASA could be added to antibody-hormone mixture in order to separate antibody-bound from free antigen. Both methods compared favorably with the more standard double-antibody method in each system tested. Antibodies produced by rabbits, guinea pigs, monkeys, and humans were precipitated equally by PASA and double antibody, whereas antibody raised in sheep was precipitated much less by PASA than by double antibody. Antibody bound to PASA was found to reach equilibrium of binding more slowly than unbound antibody for both rapid (TRH) and slow (rPRL) reactions. Binding of either free of complexed IgG by PASA, however, was extremely rapid, reaching equilibrium in less than 30 sec. This rapid binding was utilized in kinetic experiments which would not have been possible with slower-reacting precipitating agents. The versatility permitted by this propertly constitutes one of the most useful characteristics of PASA. Other important attributes of PASA include its convenience, economy, and wide applicability.

UI	MeSH Term	Description	Entries
D007074	Immunoglobulin G	The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.	Gamma Globulin, 7S,IgG,IgG Antibody,Allerglobuline,IgG(T),IgG1,IgG2,IgG2A,IgG2B,IgG3,IgG4,Immunoglobulin GT,Polyglobin,7S Gamma Globulin,Antibody, IgG,GT, Immunoglobulin
D007164	Immunosorbents	An insoluble support for an ANTIGEN or ANTIBODIES that is used in AFFINITY CHROMATOGRAPHY to adsorb the homologous antibody or antigen from a mixture. Many different substances are used, among them SEPHAROSE; GLUTARALDEHYDE; copolymers of ANHYDRIDES; polyacrylamides, etc.	Immunoadsorbent,Immunoadsorbents,Immunosorbent
D008722	Methods	A series of steps taken in order to conduct research.	Techniques,Methodological Studies,Methodological Study,Procedures,Studies, Methodological,Study, Methodological,Method,Procedure,Technique
D011388	Prolactin	A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate.	Lactogenic Hormone, Pituitary,Mammotropic Hormone, Pituitary,Mammotropin,PRL (Prolactin),Hormone, Pituitary Lactogenic,Hormone, Pituitary Mammotropic,Pituitary Lactogenic Hormone,Pituitary Mammotropic Hormone
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D000906	Antibodies	Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
D000936	Antigen-Antibody Complex	The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.	Immune Complex,Antigen-Antibody Complexes,Immune Complexes,Antigen Antibody Complex,Antigen Antibody Complexes,Complex, Antigen-Antibody,Complex, Immune,Complexes, Antigen-Antibody,Complexes, Immune
D013006	Growth Hormone	A polypeptide that is secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Growth hormone, also known as somatotropin, stimulates mitosis, cell differentiation and cell growth. Species-specific growth hormones have been synthesized.	Growth Hormone, Recombinant,Pituitary Growth Hormone,Recombinant Growth Hormone,Somatotropin,Somatotropin, Recombinant,Growth Hormone, Pituitary,Growth Hormones Pituitary, Recombinant,Pituitary Growth Hormones, Recombinant,Recombinant Growth Hormones,Recombinant Pituitary Growth Hormones,Recombinant Somatotropins,Somatotropins, Recombinant,Growth Hormones, Recombinant,Recombinant Somatotropin
D013205	Staphylococcal Protein A	A protein present in the cell wall of most Staphylococcus aureus strains. The protein selectively binds to the Fc region of human normal and myeloma-derived IMMUNOGLOBULIN G. It elicits antibody activity and may cause hypersensitivity reactions due to histamine release; has also been used as cell surface antigen marker and in the clinical assessment of B lymphocyte function.	Protein A,Protein A, Staphylococcal
D013972	Thyrotropin	A glycoprotein hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Thyrotropin stimulates THYROID GLAND by increasing the iodide transport, synthesis and release of thyroid hormones (THYROXINE and TRIIODOTHYRONINE). Thyrotropin consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the pituitary glycoprotein hormones (TSH; LUTEINIZING HORMONE and FSH), but the beta subunit is unique and confers its biological specificity.	Thyroid-Stimulating Hormone,TSH (Thyroid Stimulating Hormone),Thyreotropin,Thyrotrophin,Hormone, Thyroid-Stimulating,Thyroid Stimulating Hormone