Solid-phase Radioimmunoassay Procedure Research Articles

Radioimmunoimaging of human small cell lung carcinoma with I-131 tumor specific monoclonal antibody.

In this study, an IgM monoclonal antibody (MAb600D11) directed against human small cell lung cancer (NCI-H69) was radiolabeled with iodine-131, and the biodistribution and image quality of the radiolabeled antibody was evaluated. Radiolabeling was achieved in a solid-phase system consisting of 1,3,4,6-tetrachloro-3a,6a-diphenylglycoluril. Labeling efficiencies and protein purification were accomplished using gel exclusion chromatography while radioimmunoreactivity was determined using a solid-phase radioimmunoassay procedure. The biodistribution of I-131-labeled MAbs was determined in Sprague-Dawley rats up to 7 days after injection. Highest organ concentrations were observed in liver (3.91 +/- 0.47 (SD) and 0.17 +/- 0.04 (SD) mean percent injected dose at 1-7 days after injections) and in thyroid (5.33 +/- 0.71 (SD) and 5.32 +/- 2.01 (SD) mean percent injected dose at 1-7 days after injection). Nude mice, bearing either a small cell lung tumor (NCI-H69) or a nonspecific tumor (adenocarcinoma), were injected with 400-800 microCi of I-131 labeled monoclonal antibody. Optimum tumor visualization was observed 2-4 days after injection with tumor concentrations as high as 10.4% of the initial injected dose. The results demonstrated that radioimmunoimaging of human small cell lung carcinoma was feasible with the tumor-specific IgM I-131-labeled MAb.

Quantitation of sheep IgG1, IgG2, IgA, IgM and albumin by radioimmunoassay

A solid phase radioimmunoassay procedure for the measurement of immunoglobulins (IgG1, IgG2, IgA and IgM) and albumin in sheep body fluids (serum, intestinal lymph, caudal mediastinal lymph, bile, mammary secretions and intestinal secretions) is described. This method was found to be easy to perform, rapid, sensitive and reproducible. Results obtained were consistent with those previously reported using radial immunodiffusion and nephelometric techniques.

Evaluation of the solid-phase radioimmunoassay for diagnosis of St. Louis encephalitis infection in humans.

Since the use of highly purified viral proteins in the solid-phase radioimmunoassay (SPRIA) procedure is not practical for routine diagnostic serology, the procedure was adapted for use with the crude antigens now commonly used to diagnose St. Louis encephalitis (SLE) virus infections. SLE and various other alpha- and flavivirus antigens were tested by both the SPRIA procedure and conventional serological methods. Standards were established for use of the crude antigens in the SPRIA procedure. Reproducibility of the procedure was similar to that of conventional tests. The SPRIA procedure specifically differentiated SLE from clinically similar alphaviruses, but did not differentiate SLE from related flaviviruses very well. SPRIA diagnosis of SLE infections by the immunoglobulin G response in paired sera was good. Generally, the crude antigen SPRIA procedure was as sensitive as the conventional serological tests, but not as specific.

Mouse Hybrid Cell Lines produce Antibodies to Herpes Simplex Virus Type 1

A solid-phase radioimmunoassay procedure has been devised for the assay of antibodies produced in the mouse to herpes simplex virus type 1 (HSV-1). It is based on the adsorption of virus to flexible micro-well plates and uses radio-iodine-labelled rabbit antibody against mouse immunoglobulin to assess antibody binding. Using this assay for screening, cell hybrids have been obtained which yield monoclonal antibody to HSV-1. The hybrids are between spleen cells from hyperimmune mice and an immunoglobulin-non-secreting, azaquanine resistant myeloma cell line (NS-1). From 480 hybrid cell lines initially examined, five stable cell lines were obtained which released HSV-1-specific antibody in vitro and in vivo. Mice carrying transplants of these cell lines yield binding titres in serum of up to 1/25000. Both IgG and IgM antibodies were obtained in this way.

Partially purified antibodies used in a solid-phase radioimmunoassay for detecting candidal antigenemia

The development of a solid-phase radioimmunoassay procedure for the detection of Candida albicans antigens in serum of mice is described. Antibodies against C. albicans that were used in the radioimmunoassay procedure were partially purified from immune serum by a C. albicans antigen-coupled affinity column. Elution of anti-C. albicans antibodies from the column was by glucose and mannose; 4 mg of protein was recovered per ml, which contained 50% of the candidal agglutinin activity of immune serum. Also, 81% of the protein (partially purified antibody) recovered was adsorbed by whole C. albicans cells. Anti-C. albicans antibodies were either coupled to Sepharose 4B for use as the solid phase to bind candidal antigen in serum of infected animals, or radioiodinated (125I) for use as a tracer molecule to bind to the candidal antigen solid-phase complex. Although control experiments indicated that at least 100 ng of candidal antigen should be present in a serum specimen for a positive radioimmunoassay test, candidal antigenemia was detected in 70.4% of infected mice even in cases where blood cultures for C. albicans were negative. With further refinement and adaptability to human serum, the radioimmunoassay test may become a helpful tool for use in the diagnosis of systemic candidiasis.

Procedures for Characterizing Certain Effects of Prolonged Noise Exposure

An interdisciplinary research team at the Pennsylvania State University examined the effects of long duration (16 hours), continuous exposure to an 85 dBA broad band noise in human subjects. Both noise exposure and control (without noise) experiments were completed. The test battery included measurements of blood hormone (cortisol) levels, temporary hearing threshold shift (TTS), loudness discrimination index (LDI) and level of initial masking (LIM). Blood samples were collected in heparinized tubes, centrifuged and the plasma samples were analyzed for circulating levels of cortisol using a solid phase radioimmunoassay procedure. In the audiometric tests, the performance changes for the tasks of threshold sensitivity (TTS) identification of small increments in a tonal stimulus (LDI) and recognition of a tonal stimulus in a frequency-varying tonal masker (LIM) were examined by comparing test results before and after the experimental condition (either 85 dBA noise or low level ambient sound, for 16 h). The results of the investigation are discussed with particular attention to the effectiveness of the test battery in characterizing the effects of the noise and to the elucidation physiological correlates that may underlie certain audiometric phenomena that follow noise exposure. [This project was funded, in part, by a Rockefeller Foundation Grant-in-aid.]

Solid-phase radioimmunoassay method for determination of Escherichia coli enterotoxin.

The development of a solid-phase radioimmunoassay procedure for the determination of Escherichia coli enterotoxin(s) is described. Radioiodinated E. coli enterotoxin with about three radioiodine atoms per toxin molecule is, by the criterion of electrophoresis, identical to the unlabeled toxin. Goat anti-E. coli-enterotoxin antibody was coupled to polystyrene tubes and served as a solified toxin binder in the reported procedure. Various conditions necessary for the optimization and standardization of the solid-phase method were established. With the help of this technique it was possible to determine E. coli enterotoxin released from a porcine E. coli strain into culture medium.

Highly sensitive solid-phase radioimmunoassay suitable for determination of low amounts of cholera toxin and cholera toxin antibodies.

A direct solid-phase radioimmunoassay procedure was developed for the determination of cholera toxin and cholera toxin antibody. The reported method employed anti-choleragenoid antibody attached to polystyrene tubes as a solidified binder for cholera toxin. The binding of radioidinated cholera toxin on its solidified antibody was inhibitable by unlabeled cholera toxin and cholera toxin antibody. With the help of this method, the heat stability of cholera toxin was also studied. Radioiodinated cholera toxin was shown to be labeled in both of its subunits. The stability of the iodinated cholera toxin at the reported specific radioactivity is remarkable. It was found that the labeled cholera toxin can be used in the solid-phase radioimmunoassay even 4 months after iodination.

A solid phase radioimmunoassay for pancreatic glucagon.

A solid phase radioimmunoassay procedure has been applied for the determination of glucagon and some variables of the assay procedure were studied. The sensitivity of the assay was 10 pg of glucagon for samples assayed in triplicate. This assay method which has a high precision and is technically simple as compared with other radioimmunoassays, was found to be suitable for studies on glucagon release in vitro.

Tartrazine: solid-phase radioimmunoassay studies of an azo dye implicated in allergic reactions (azo dyes and allergy).

A solid-phase radioimmunoassay procedure was adapted for the haptenic study of tartrazine, an azo dye implicated in various forms of allergy. Further, the haptenic relationship of tartrazine and aspirin was investigated, since sensitivity of individuals to the two substances is often clinically associated. The specificity of antibody to tartrazine was directed strongly toward a pyrazolone intermediate of the molecule, 1-(4-sulfophenyl)-3-carboxy-5-hydroxy-pyrazole. Aspirin did not cross-react with anti-tartrazine, suggesting that the clinical association of aspirin and tartrazine sensitivity in patients is a nonimmunological phenomenon.

Quantitation of Serum IgG by Solid-Phase Radioimmunoassay

Abstract Human serum immunoglobulins are most frequently measured by single gel diffusion. Radioimmunoassay by use of antibodies bonded to particles is faster and more sensitive, precise, accurate, and specific. We adopted a solid-phase radioimmunoassay (SPRIA) technique, developed in our laboratory, to measure serum IgG, and compared the results with those of a gel-diffusion method commonly used to measure serum IgG. The SPRIA technique is based on competition set up between antibodies to human IgG chemically bonded to cellulose particles and a purified serum IgG labeled with 125I. The solid phase permits prompt separation of the bound from free labeled reagent. We studied precision, accuracy, sensitivity, and specificity, as compared to gel diffusion; values for the two methods agreed well for 57 sera from hospital patients. The SPRIA procedure is more precise, and can be completed in 3 h, as compared to the 16-24 h normally required for gel diffusion procedures. The possible automation of SPRIA is discussed.