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Results for “Immunosorbents”

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At least 19 recordsLinked to original sources

PubMed1992

Detection of chronic hepatitis C virus infection by four diagnostic systems: first-generation and second-generation enzyme-linked immunosorbent assay, second-generation recombinant immunoblot assay and nested polymerase chain reaction analysis.

Serum samples from 100 patients with non-A, non-B hepatitis-related chronic liver disease and 100 patients with hepatitis B-related chronic liver disease were tested by first-generation and second-generation enzyme-linked immunosorbent assays, a second-generation recombinant immunoblot assay and the nested polymerase chain reaction. In non-A, non-B hepatitis-related chronic liver disease, second-generation enzyme-linked immunosorbent assay (anti-c22 and/or c200) and second-generation recombinant immunoblot assay showed 98% positivity, whereas first-generation enzyme-linked immunosorbent assay (anti-c100-3) showed 89% positivity. The two second-generation recombinant immunoblot assay-negative samples were positive by nested polymerase chain reaction, but one second-generation recombinant immunoblot assay-positive sample was polymerase chain reaction negative. However, when this second-generation recombinant immunoblot assay-positive sample was tested by polymerase chain reaction using another set of primers, it was polymerase chain reaction positive. Therefore, 100% of the non-A, non-B hepatitis-related chronic liver disease serum samples were hepatitis C virus RNA positive by polymerase chain reaction. Nine hepatitis B-related chronic liver disease samples were first-generation enzyme-linked immunosorbent assay positive. Of the eight second-generation enzyme-linked immunosorbent assay-positive hepatitis B-related chronic liver disease samples, six were first-generation enzyme-linked immunosorbent assay positive and five were second-generation recombinant immunoblot assay positive and polymerase chain reaction positive. One indeterminate second-generation recombinant immunoblot assay sample was polymerase chain reaction negative. Therefore, second-generation recombinant immunoblot assay appears to be as useful as polymerase chain reaction for detecting a chronic hepatitis C virus infection, although some discrepancies were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1975

Studies on the purification of chlamydial agents grown in yolk sacs of embryonated eggs using disulphide-linked immunosorbents and enzymes.

Immunosorbents were derived from avid and non-avid sera raised in rabbits to multiple or single injections of chlamydiae passaged once or three times in HeLa cells after routine passage in eggs. Egg-derived suspensions of chlamydiae required pretreatment before application to immunosorbent columns; this was most conveniently done by fractionation on Sepharose 4B. Immunosorbents derived from avid serum had greater capacity than those from non-avid sera. However, organisms were desorbed in low yield from an avid immunosorbent, but in higher yields from non-avid immunosorbents. Even under the best conditions, the immunosorbents yielded suspensions of organisms still contaminated with egg antigens. Partially purified suspensions of chlamydiae were also treated with phospholipase C to yield suspensions of high purity.

Adsorption↗

PubMed1979

Comparison of enzyme-linked immunosorbent assay and passive hemagglutination method for quantification of antibodies to lipopolysaccharide and tetanus toxoid in rats.

In a comparative study, the enzyme-linked immunosorbent assay, using peroxidase labeled anti-rat immunoglobulin M and immunoglobulin G, and the passive hemagglutination test were applied to determine the primary and secondary antibody response to lipopolysaccharide and tetanus toxoid in rats. In the enzyme-linked immunosorbent assay, the antigens were bound to the wells of polystyrene microplates, tetanus toxoid directly, and lipopolysaccharide after complexing it with methylated bovine serum albumin. After incubation with dilutions of the rat sera, the amount of antibody bound to the solid phase was quantified by means of peroxidase-labeled anti-immunoglobulin. The specificity of the enzyme immunoassay was tested by absorption of the sera with their respective antigens. The enzyme-linked immunosorbent assay proved to be more sensitive than the hemagglutination reaction, except when titers were determined during the secondary response to tetanus toxoid. Besides its specificity and sensitivity, the enzyme-linked immunosorbent assay is a convenient method for measuring both immunoglobulin M and immunoglobulin G antibodies. At low serum dilutions of lipopolysaccharide antisera, inhibition of the reaction in the enzyme-linked immunosorbent assay occurred. This phenomenon could be prevented by heating the sera at 56 degrees C for 30 min. Lipopolysaccharide was immunogenic in rats over an extremely wide dose range (from 10 pg to 1 mg); the optimal immunogenic dose of lipopolysaccharide for young adult rats was 0.1 to 1,000 mug when administered intravenously, and that of tetanus toxoid was 5 to 10 lines of flocculation, as determined by the Ramon flocculation test.

Animals↗

PubMed1979

Method for continuous purification of biological material using immunosorbent.

A mechanical device for the continuous purification of biological material using immunosorbent was developed. The system consists of heat-sealed nylon pouches containing agarose-bound antibody, attached to an endless 35 mm wide Mylar belt that passes through four chambers sequentially. The biological material is bound and dissociated, and the immobilized antibody is regenerated for repeated isolation and purification of antigen. The belt design incorporates features to minimize carry-over between chambers and prevent damage to the agarose-bound antibody in repeated passes through the system. An existing batch method for the purification of human placental alkaline phosphatase using immobilized rabbit antisera was adapted to continuous purification in the device. The belt contained a low affinity immunosorbent and made five complete passes through the system. A decrease in antigen binding capacity between free immunosorbent suspensions and belt immunosorbent in pouches was observed. This was shown to be the result of the diffusion resistance offered by the pouch and the short exposure times of each pouch in the chambers. A decrease in antigen binding capacity between successive belt passes was also observed, and resulted from the inability of the agarose in the pouches to resuspend completely after each pass. The low efficiency of the agitation method and the roller device used to squeeze the pouches were the reasons for this deficiency.

Alkaline Phosphatase↗

PubMed1979

Enzyme-linked protein A: an enzyme-linked immunosorbent assay reagent for detection of human immunoglobulin G and virus-specific antibody.

A general-purpose reagent capable of reacting with immunoglobulin G in a modified enzyme-linked immunosorbent assay technique was prepared by using protein A coupled with horseradish peroxidase. The reagent detected low levels (0.003 to 1.0 microgram/ml) of human immunoglobulin G and was also applied in an enzyme-linked immunosorbent assay for titration of antibody to human cytomegalovirus. The antibody titers to human cytomegalovirus determined by enzyme-linked immunosorbent assay and by complement fixation were compared. The correlation coefficient between the two techniques was 0.85, but the enzyme-linked immunosorbent assay was 10 times more sensitive than complement fixation in terms of antibody titers detected.

Antibodies, Viral↗

PubMed1975

Comparison of antigen-type immunosorbents prepared by different ways.

7 types of IgG-containing immunosorbents were compared from different respects by using them for adsorption of antibodies. The human IgG was insolubilized by ethylchlorophormate and glutaraldehyde, thereafter it was bound to activated agarose and polyacrylamide gels and 3 new types of polyacrylamide immunosorbent were prepared by polymerizing the acrylamide in the protein solution and by coupling the protein to the matrix by different ways. Using batch technique, the ethylchlorophormate, the glutaraldehyde and some of the new polyacrylamide immunosorbents proved to be useful, but in almost every respect the immunosorbent prepared from Sepharose gel was the best.

Antibodies↗

PubMed1979

An enzyme-linked immunosorbent assay for the detection of canine antibodies to canine adenoviruses.

An enzyme-linked immunosorbent assay was used to detect canine immunoglobulin G antibodies specific for infectious canine hepatitis virus and the serologically related canine adenovirus Type 2. The sequential development of homologous and heterologous antibodies was measured by the enzyme-linked immunosorbent assay and serum neutralization tests in two groups of dogs which were experimentally infected with either infectious canine hepatitis virus or canine adenovirus Type 2. Both tests were comparable in their abilities to detect the development of homologous and heterologous antibodies. Homologous antibodies were detected earlier and to a higher titer in both tests. There was a 98% agreement between the serum neutralization test and the enzyme-linked immunosorbent assay when sera from 224 random-source dogs were examined for infectious canine hepatitis virus antibodies. The enzyme-linked immunosorbent assay was found to be a highly efficient and rapid test to determine the immune status of dogs to infectious canine hepatitis virus and canine adenovirus Type 2.

Adenoviridae↗

PubMed1976

A galactosidase immunosorbent test for carcinoembryonic antigen.

A galactosidase immunosorbent test for carcinoembryonic antigen (CEA) is described in which the amount of galactosidase adsorbed to a cellulose disc is a hyperbolic function of CEA concentration. Thus, molecules with CEA-like activity can be characterized by mathematical analysis of data obtained from the galactosidase immunosorbent test. By such analysis, CEA-reactive molecules in normal human plasma were distinguished from normal cross-reacting antigen and from authentic CEA. Variation of the amount of antibody-enzyme conjugate used in the galactosidase immunosorbent test permitted CEA-reactive material in plasma of a patient with rectal carcinoma to be antigenically distinguished from the CEA-reactive material in urine of a patient with bladder carcinoma. The galactosidase immunosorbent test is a useful tool for analysis of CEA-reactive molecules.

Absorption↗

PubMed1977

Thermometric enzyme linked immunosorbent assay: TELISA.

A new method, thermometric enzyme linked immunosorbent assay (TELISA), for the assay of endogenous and exogenous compounds in biological fluids is described. It is based on the previously described enzyme linked immunosorbent assay technique, ELISA, but utilizes enzymic heat formation which is measured in an enzyme thermistor unit. In the model system studied determination of human serum albumin down to a concentration of 10(-10) M (5 ng/ml) was achieved, with both normal and catalase labelled human serum albumin competing for the binding sites on the immunosorbent, which was rabbit antihuman serum albumin immobilized onto Sepharose CL-4B.

Catalase↗

PubMed1978

[Isolation of antilymphocytic antibodies with the aid of cellular immunosorbents].

The authors suggest a method of obtaining purified antilymphocytic antibodies by mean of a specific immunosorbent of human or mouse lymphocytes fixated with glutharic aldehyde Such immunosorbents subjected to special treatment could be used repeatedly; their sorptive capacity was retained in such case. Only from 5 to 12% of the activity could be obtained from immunosorbents sorbed from the serum with 77--93% activity. In comparison with the initial serum, purification was from 6- to 15-fold. Thus, the suggested method provided considerable purification of the antilymphocytic preparations and permitted to obtain highly active antilymphocytic antibodies.

Aldehydes↗

PubMed1979

A comparison of different enzyme-antibody conjugates for enzyme-linked immunosorbent assay.

Calf intestinal alkaline phosphatase (CIAP)- and horseradish peroxidase (HRP)-linked goat antibody (Ab) conjugates have been prepared by two procedures. One procedure is by glutaraldehyde coupling of the proteins; the other is by intermolecular disulfide bond formation of the appropriately modified proteins. The conjugates, specific for rabbit IgG, were tested for their effectiveness as reagents in enzyme-linked immunosorbent assays for ragweed antigen E specific rabbit antibody. The CIAP-Ab conjugate prepared by glutaraldehyde coupling and the HRP-Ab conjugate made by disulfide bond formation were equally effective reagents for immunoassay, but the HRP-Ab conjugate obtained by glutaraldehyde coupling was definitely less useful than the other two conjugates. The assay procedure utilized an antigen E coupled paper disc as the immunosorbent and it was sensitive in the range of 0.5--100 ng per test. Inhibition of the enzyme-linked immunosorbent assay was used as a sensitive technique for measuring antigenic activity of antigen E or its derivatives.

Alkaline Phosphatase↗

PubMed1978

Enzyme-linked immunosorbent assay for measurement of serological response to respiratory syncytial virus infection.

An enzyme-linked immunosorbent assay was applied to the detection of serum antibodies against respiratory syncytial virus. The end points of the various sera tested in the assay were approximately 100 times higher than in the complement-fixation test and 2 to 4 times higher than in the plaque reduction test. In addition, the immunosorbent assay appeared to be more efficient than the plaque reduction and complement-fixation techniques for detecting a serological response in young infants (1 to 6 months old) with serous respiratory syncytial virus lower respiratory disease. The simplicity, sensitivity, and rapidity of the enzyme-linked immunosorbent assay make it a useful tool for immunological studies with respiratory syncytial virus.

Antibodies, Viral↗

PubMed1979

Enzyme-linked immunosorbent assay for detection of antibodies to murine hepatitis virus.

An enzyme-linked immunosorbent assay was developed for the detection of antibodies to murine hepatitis virus. A high prevalence of antibody to murine hepatitis virus was found by the enzyme-linked immunosorbent assay in colonies with a low prevalence of complement-fixing antibodies. Murine hepatitis virus strain A59 was found to be broadly reactive as an enzyme-linked immunosorbent assay antigen.

Age Factors↗

PubMed1979

Solid-phase enzyme-linked immunosorbent assay for detection of hepatitis A-specific immunoglobulin M.

A solid-phase enzyme linked immunosorbent assay was developed for the detection of immunoglobulin M antibody to hepatitis A virus. The system was capable of detecting hepatitis A-specific immunoglobulin M in a single dilution of serum and appears to be a reliable and rapid means of establishing a diagnosis of hepatitis A infection. Specific immunoglobulin M was only detected in patients with serologically confirmed hepatitis A and not in patients with other forms of hepatitis, chronic liver disease, or autoimmune disease. In patients with hepatitis A, specific immunoglobulin M was usually detectable for 6 weeks after the onset of dark urine, and the longest period for which it was present in any patient was 115 days. This enzyme-linked immunosorbent assay is rapid, simple to perform, and does not require complicated equipment. Provided adequate supplies of purified reagents can be obtained, this enzyme-linked immunosorbent assay procedure is likely to simplify hepatitis A serology, because the same antibody-coated plates can be utilized to detect hepatitis A virus, anti-hepatitis A virus, and hepatitis A-specific immunoglobulin M.

Antibodies, Viral↗

PubMed1976

Application of a galactosidase immunosorbent test to carcinoembryonic antigen in plasma.

The galactosidase immunosorbent test for carcinoembryonic antigen is simple to perform, uses stable reagents, does not require radioactive reagents, and is adaptable to large numbers of samples. Concentration of carcinoembryonic antigen in sera or plasma was determined by the galactosidase immunosorbent test and by the Egan-Todd double antibody assay (93% agreement), indirect Z-gel (83% agreement), and direct Z-gel assay (ps = 0.97). The galactosidase immunosorbent test has potential as a clinically useful nonisotopic assay for carcinoembryonic antigen.

Antibody Specificity↗

PubMed1992

Early diagnosis of enteroviral meningitis by detection of specific IgM antibodies with a solid-phase reverse immunosorbent test (SPRIST) and mu-capture EIA.

A solid-phase reverse immunosorbent test (SPRIST) and a mu-capture enzyme immunosorbent assay (EIA) for detection of enterovirus-specific IgM antibodies were evaluated for enterovirus diagnosis of aseptic meningitis in 160 consecutive patients from whom enterovirus (11 different serotypes) were isolated in 64. In patients with an enterovirus isolate and/or four-fold titre rise in the complement fixation test (CFT) for enterovirus, specific enterovirus IgM antibodies were detected on the day of admission to hospital in 48% by SPRIST and in 50% by EIA and 4-6 days after onset of symptoms in 71% by SPRIST and 79% by EIA. A significant increase in titre was observed between serum sampled on the day of admission and 2 days later in 38% by SPRIST and in 41% by EIA. These results indicate that the IgM antibody response appears early in the course of aseptic meningitis. Since both SPRIST and EIA provide rapid results the tests may be of differential diagnostic value and the IgM antibody kinetics may be utilized for diagnosis during the acute phase of aseptic meningitis. With optimized serum sampling the positive outcome was 76% in SPRIST and 82% in EIA among patients with positive virus isolation and/or CFT for enterovirus. In 67 patients virus isolation and CFT for enterovirus yielded negative results as well as all non-enteroviral diagnostic tests. Thirty-eight of these patients were positive by SPRIST and/or EIA and in half of these 38 a significant titre rise and/or fall in SPRIST and/or EIA was recorded. The majority of these IgM-positive patients became ill in the late summer or autumn, i.e., the "enterovirus season."(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

[Possibility of selective binding of HIV-1 infected cells by immunosorbents].

A study was made of a possibility of specific sorption of HIV-1 infected cells with gamma-fraction of AIDS patients' serum containing high titer-specific antibodies, immobilized on the silica matrix (C-3). The laboratory tests were made with the use of the monocyte culture [symbol: see text] chronically infected with HIV-1. In addition to a decrease of the cell count after sorption, there was a decline of the activity of antigen material in the samples (to 43% of the initial). The selectivity rates were 0.92 for immunosorbents and 0.29 for sorbents of the control group, that confirms and increase of the delay of the cells expressing HIV-1 proteins on a column with the immobilized gamma-fraction of AIDS patients' serum. The use of the synthesized immunosorbents in vivo may appear debatable. However, this method can be employed for preparative purposes.

Acquired Immunodeficiency Syndrome↗

PubMed1978

Reversed immunosorbents: a simple method for specific antibody immobilization.

A method is presented for permanently converting an antigen immunosorbent into a purified antibody immunosorbent which retains specific reactivity for antigen. Following immunological reaction of the antibodies in an antiserum with the antigen adsorbent, the specific immunoglobulin is chemically bound to the antigen by means of the divalent crosslinking agent. Various such agents, including glutaraldehyde, suberimidate, a diazide, and isocyanates, were employed. The conditions of preparation using the first two were optimized, and the characteristics of the resulting immobilized antibodies were investigated. Applications in radioimmunoassay, preparative chromatography, and affinity-constant studies discussed in view of the unique attributes of these reagents.

Animals↗