scholarly journals Single-Dilution Enzyme-Linked Immunosorbent Assay for Quantification of Antigen-Specific Salmonid Antibody

2000 ◽  
Vol 12 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Stewart W. Alcorn ◽  
Ronald J. Pascho
Keyword(s):  
Immunosorbent Assay ◽  
Sockeye Salmon ◽  
High Titer ◽  
Repeated Measurements ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Activity ◽  
Standard Curve ◽  
Test Fish ◽  
The Mean ◽  
Antibody Levels

An enzyme-linked immunosorbent assay (ELISA) was developed on the basis of testing a single dilution of serum to quantify the level of antibody to the p57 protein of Renibacterium salmoninarum in sockeye salmon ( Oncorhynchus nerka). The levels of antibody were interpolated from a standard curve constructed by relating the optical densities (OD) produced by several dilutions of a high-titer rainbow trout ( O. mykiss) antiserum to the p57 protein. The ELISA OD values produced by as many as 36 test sera on each microplate were compared with the standard curve to calculate the antigen-specific antibody activity. Repeated measurements of 36 samples on 3 microplates on each of 6 assay dates indicated that the mean intraassay coefficient of variation (CV) was 6.68% (range, 0–23%) and the mean interassay CV was 8.29% (range, 4–16%). The antibody levels determined for the serum sample from 24 sockeye salmon vaccinated with a recombinant p57 protein generally were correlated with the levels determined by endpoint titration ( r2 = 0.936) and with results from another ELISA that was based on extrapolation of antibody levels from a standard curve ( r2 = 0.956). The single-dilution antibody ELISA described here increases the number of samples that can be tested on each microplate compared with immunoassays based on analysis of several dilutions of each test serum. It includes controls for interassay standardization and can be used to test fish weighing <3 g.

scholarly journals Antibody level of New Zealand children immunized with the triple vaccine DTP (diphtheria-tetanus-pertussis)

1988 ◽  
Vol 101 (2) ◽  
pp. 405-410 ◽  
Author(s):  
R. C. H Lau
Keyword(s):  
New Zealand ◽  
Immunosorbent Assay ◽  
Antibody Level ◽  
Herd Immunity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Immunization Strategy ◽  
The Mean ◽  
Antibody Levels

SUMMARYEnzyme-linked immunosorbent assay (ELISA) tests were used to measure IgG antibody levels in 2638 New Zealand children who had been immunized with the triple vaccine DTP. The percentage of children immune to diphtheria decreased with age. The percentage of children immune to tetanus varied from 67.1 to 55.0%. The percentage of children with measurable antibody to pertussis increased with age. The mean percentages of children with measurable antibody or immunity to one or more DTP components were 34.2% (with 3 components), 34.4% (2 components), and 78.1% (1 component). It appears the immunization strategy for diphtheria and tetanus is satisfactory for herd immunity in New Zealand children. However, the current pertussis strategy may not be providing adequate immunity to 5-year-olds in this country.

scholarly journals Enzyme-Linked Immunosorbent Assay for Measurement of Cytomegalovirus Glycoprotein B Antibody in Serum

2010 ◽  
Vol 17 (5) ◽  
pp. 836-839 ◽  
Author(s):  
Daniel J. Hackett ◽  
Changpin Zhang ◽  
Carla Stefanescu ◽  
Robert F. Pass
Keyword(s):  
Immunosorbent Assay ◽  
Geometric Mean ◽  
Mean Value ◽  
Glycoprotein B ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Negative Results ◽  
Wide Range ◽  
The Mean ◽  
Antibody Levels

ABSTRACT Measurement of antibody to cytomegalovirus (CMV) glycoprotein B (gB) is valuable in the assessment of the antibody response to infection and to gB-containing vaccines. For this purpose, an enzyme-linked immunosorbent assay (ELISA) with a recombinant CMV gB molecule as the antigen was evaluated. Sera from 168 anti-CMV IgG-positive and 100 seronegative subjects were used to evaluate the anti-gB antibody assay. A cutoff optical density (OD) that would distinguish gB antibody-positive from -negative sera was established. Titers of antibody to gB determined by endpoint dilution were compared with those calculated using regression analysis. The run-to-run and interoperator reproducibilities of results were measured. The mean OD + 5 standard deviations from 50 anti-CMV IgG antibody-negative sera (0.2472) was used as the cutoff between anti-gB antibody-positive and -negative results. All sera from 100 anti-CMV IgG-seronegative subjects were negative for antibody to gB. All but 1 of 168 sera from seropositive subjects were positive for antibody to gB. Observed antibody levels based on titration to the endpoint were very similar to results calculated using linear regression. The run-to-run consistency of endpoints was excellent, with 38 runs from one operator and 48 runs from another all giving results within 1 dilution of the mean value for each of three anti-CMV IgG antibody-positive serum pools. The geometric mean titer of antibody to gB for 99 sera from seropositive blood donors was 1/10,937. This ELISA gives accurate and reproducible results for the relative quantity of anti-CMV gB IgG in serum over a wide range of antibody levels.

Humoral Immunity to Myxoma Virus in Wild Rabbits.

1983 ◽  
Vol 10 (2) ◽  
pp. 277 ◽  
Author(s):  
JD Wetherall ◽  
DE Clay ◽  
DR King
Keyword(s):  
Immunosorbent Assay ◽  
Humoral Immunity ◽  
Western Australia ◽  
Gel Filtration ◽  
Myxoma Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Activity ◽  
Virus Antibody ◽  
Serum Samples ◽  
Antibody Levels

An enzyme linked immunosorbent assay was developed to detect antibody to myxoma virus in serum of rabbits. In ten laboratory rabbits vaccinated with attenuated myxoma virus, antibody levels were seen to increase for four weeks, after which they declined. Antibody levels in a large number of wild rabbits collected at Cape Naturaliste area, Western Australia, in 1974 were high, following an outbreak of myxomatosis. When serum samples from the same population were tested in 1978, levels of antibody were low. Using gel filtration chromatography, the main anti-myxoma virus antibody activity seemed to be in the IgG fraction, although IgM and IgA were also present.

scholarly journals Enzyme-linked immunosorbent assay determination of specific rubella antibody levels in micrograms of immunoglobulin G per milliliter of serum in clinical samples

1978 ◽  
Vol 8 (4) ◽  
pp. 419-423
Author(s):  
P O Leinikki ◽  
I Shekarchi ◽  
P Dorsett ◽  
J L Sever
Keyword(s):  
Immunosorbent Assay ◽  
Immunoglobulin G ◽  
Solid Phase ◽  
Laboratory Diagnosis ◽  
Clinical Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Standard Curve ◽  
Antibody Levels

A "microgram assay" is described in which solid-phase enzyme-linked immunosorbent assay is used for the determination of specific rubella immunoglobulin G (IgG) antibody levels in micrograms per milliliter of serum. The quantitation was based on a standard curve obtained by using a reference serum, for which the specific IgG content was assayed by immunochemical purification. IgG was first purified and specific rubella antibodies were separated by an immunoadsorbent prepared by linking rubella virus antigens to Sepharose 4B. By using IgG-specific conjugate, the levels of specific rubella IgG antibodies could then be determined from clinical samples. Seronegative samples showed antibody levels less than 1 microgram/ml, whereas levels up to several hundred micrograms per milliliter were detected in some postinfection sera. The correlation between microgram antibody levels and hemagglutination inhibition titers was linear. The method offers a simple and sensitive antibody assay which could be used both for the laboratory diagnosis of acute rubella and for the evaluation of immunity.

Quantitative Evaluation of Pork Adulteration in Raw Ground Beef by Radial Immunodiffusion and Enzyme-Linked Immunosorbent Assay

1998 ◽  
Vol 61 (12) ◽  
pp. 1686-1690 ◽  
Author(s):  
DAVID R. MARTIN ◽  
JOYCE CHAN ◽  
JOSEPH Y. CHIU
Keyword(s):  
Detection Limit ◽  
Immunosorbent Assay ◽  
Ground Beef ◽  
Radial Immunodiffusion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Agar Gel ◽  
Standard Curve ◽  
Quantitative Estimates ◽  
Wide Range ◽  
The Mean

Quantitative estimates are important to establish whether pork adulteration in ground beef is accidental or intentional. A standard agar gel radial immunodiffusion (RID) test using forensic-grade antiserum to porcine albumin and an enzyme-linked immunosorbent assay (ELISA) using forensic-grade anti-porcine glycoprotein immunoglobulin were used to determine from 1 to 75% raw pork in raw ground beef. The RID test, which incorporated 1.5% anti-pork serum in 1% immunodiffusion agar, formed precipitin rings with pork albumin in agar wells. A linear standard curve was obtained by plotting the diffusion area against standard pork concentrations ranging from 0 to 80%. For the ELISA the endpoint optical density increased linearly versus log % pork between 0.0625% and 2% pork. In spiked samples, the RID test had a detection limit of 3 to 5%, a coefficient of variation (CV) of 22%, and a recovery of 105%. The ELISA had a detection limit of 1%, a CV of 18%, and a recovery of 114%. The mean recovery from the spiked samples by the ELISA and RID test was not significantly different (P &gt; 0.05) from the known sample amounts. Quantitation by RID of 28 ground beef samples (27 of which were DTEK ELISA-positive for pork adulteration) revealed a wide range of pork content, with values as high as 48%.

SENSITIVE AND SPECIFIC ENZYME-LINKED IMMUNOSORBENT ASSAY FOR UROKINASE-TYPE PLASMINOGEN ACTIVATOR IN HUMAN PLASMA

1987 ◽  
Author(s):  
J Grøndahl-HANSEN ◽  
N Agerlin ◽  
L S Nielsen ◽  
K Danø
Keyword(s):  
Plasminogen Activator ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mean Values ◽  
Amino Terminal ◽  
Type Plasminogen Activator ◽  
Healthy Donors ◽  
Urokinase Type Plasminogen Activator ◽  
The Mean

An enzyme-linked immunosorbent assay (ELISA) was developed for the measurement of human urokinase-type plasminogen activator (u-PA) in plasma and serum. Microtiter plates were coated with a monoclonal antibody and incubated with standard or sample. Bound u-PA was quantitated with polyclonal antibodies conjugated with biotin, followed by avidin-peroxidase. The assay was 10-fold as sensitive as other previously reported ELISAs, the detection limit being approximately 1 pg of u-PA in a volume of 100 μl with a linear dose-response up to 15 pg of u-PA. The assay detected active u-PA and its inactive proenzyme form equally well and the recovery of both forms was higher than 90% in plasma. A variety of structurally related proteins, including t-PA, were tested, but no reaction with proteins other than u-PA and its amino-terminal degradation product were observed. The intra-assay and inter-assay coefficients of variation for determination of u-PA in plasma were 7.6% and 8.4%, respectively. The assay was equally applicable to serum. The values obtained with plasma and serum were similar, and the results were not affected by small variations in the preparation of the samples. The ELISA was used to measure the concentration of u-PA in plasma from 34 healthy donors. The mean values for u-PA in plasma from healthy donors was 1.1 ng/ml ± 0.3 ng/ml (SD) (range 0.6 - 1.5 ng/ml). No significant differences were found between men and women and no correlation between u-PA concentration and age could be demonstrated.The mean u-PA concentration in plasma from healthy donors obtained in this study is substantially lower than that reported by others. This might be due to different methods of determination of the protein content of the standard preparations or to differences in the specificity of the assays.

Comparison of an enzyme-linked immunosorbent assay for quantitation of rotavirus antibodies with complement fixation in an epidemiological survey

1978 ◽  
Vol 8 (3) ◽  
pp. 268-276
Author(s):  
L H Ghose ◽  
R D Schnagl ◽  
I H Holmes
Keyword(s):  
Immunosorbent Assay ◽  
Complement Fixation ◽  
Age Groups ◽  
Enzyme Reaction ◽  
Epidemiological Survey ◽  
Enzyme Linked Immunosorbent Assay ◽  
Marker Enzyme ◽  
Aminosalicylic Acid ◽  
Antibody Titers ◽  
Antibody Levels

The development of a micro-scale enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase as the marker enzyme for the detection and measurement of human rotavirus antibodies is described. A semipurified preparation of the serologically related simian agent, SA-11 virus, was used as the antigen. Test sera were reacted with antigen-sensitized wells in disposable poly-vinyl microplates. Any attached antibody was detected by the addition of peroxidase-labeled anti-species immunoglobulin (conjugate) followed by assay of the enzyme reaction with its substrate, hydrogen peroxide plus 5-aminosalicylic acid. This micro-ELISA was compared with complement fixation in a seroepidemiological study of the age prevalence of rotavirus antibody in Aboriginal and European populations living in the same outback area in Australia. The ELISA (results read with the naked eye) proved to be approximately 16 times more sensitive than complement fixation. Of Aborigines, 71% had rotavirus complement-fixing antibody, as compared to 45% of Europeans. By ELISA 100% of both populations had rotavirus antibodies. Mean antibody titers in the different age groups were higher in Aborigines than in Europeans. Antibody levels rose steeply throughout the first 20 years of life, remained high during the next 20 years, then increased again at least up to the age of 60 years. The micro-ELISA was practical, simple to perform, and more suitable than complement fixation for large seroepidemiological rotavirus studies. It also has potential for serodiagnosis of the disease, both in the laboratory and in the field.

scholarly journals Mycotoxins as a risk in the grain food

2009 ◽  
pp. 79-86 ◽  
Author(s):  
Jovana Matic ◽  
Jasna Mastilovic ◽  
Ivana Cabarkapa ◽  
Anamarija Mandic
Keyword(s):  
European Union ◽  
Secondary Metabolites ◽  
Ochratoxin A ◽  
Immunosorbent Assay ◽  
Toxic Effects ◽  
Enzyme Linked Immunosorbent Assay ◽  
The European Union ◽  
The Mean ◽  
Grain Foods

Mycotoxins are toxic secondary metabolites of fungi that contaminate a large variety of foods and have toxic effects on humans. The best protection against mycotoxins is to monitor their presence in food. This paper shows the screening results of mycotoxins present in 76 samples of different groups of grain foods. Samples of grain food were analyzed for contamination with aflatoxins, ochratoxin A, zearalenone, fumonisins and deoxynivalenol. Analysis were conducted using competitive enzyme-linked immunosorbent assay (ELISA). None of the samples was contaminated with aflatoxins. The most predominant mycotoxin was ochratoxin A with the mean level of 4.84 ? 4.49 ppb in 19.7% of the examined samples. Zearalenone, fumonisins, and deoxynivalenol were found in 9.21, 14.5 and 3.9% of the samples, respectively. Mycotoxin content in the investigated samples was compared with the regulations of Serbia and those of the European Union.

scholarly journals Analysis of Specific Immunoglobulin G Subclass Antibodies for Serological Diagnosis of Echinococcosis by a Standard Enzyme-Linked Immunosorbent Assay

1998 ◽  
Vol 5 (5) ◽  
pp. 613-616 ◽  
Author(s):  
Felix Grimm ◽  
Friedrich E. Maly ◽  
Jian Lü ◽  
Roberto Llano
Keyword(s):  
Healthy Volunteers ◽  
Immunosorbent Assay ◽  
Immunoglobulin G ◽  
Serological Diagnosis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Parasitic Infections ◽  
Igg Subclass ◽  
Specific Antibodies ◽  
Specific Igg4 ◽  
Antibody Levels

ABSTRACT The potential roles of specific antibodies of the different immunoglobulin G (IgG) subclasses in the serological diagnosis of cystic echinococcosis (CE) and alveolar echinococcosis (AE) were investigated by an enzyme-linked immunosorbent assay based on hydatid fluid as antigen. Specific antibodies of subclass 1 were found to be of major importance. In sera collected at the time of diagnosis (i.e., before any therapeutic intervention was initiated) they could be demonstrated in 14 of 15 sera from patients with CE and in all 12 sera from patients with AE. The most discriminatory and the most specific antibodies found in this study belonged to IgG subclass 4. Only one false-positive reaction was observed with 253 sera from healthy volunteers, and no cross-reactions occurred in 80 sera from patients with different parasitic infections. Specific IgG4 antibodies could be demonstrated in 61.0 to 66.7% (CE) or 47.6 to 66.7% (AE) of the cases. Antibody levels of IgG subclass 2 were elevated only moderately, and subclass 3 antibodies were detected in a few cases only. In addition, nonspecific reactions in sera of healthy volunteers or patients with other parasitic infections could partially be attributed to antibodies of subclasses 2 and 3.

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