Radioimmunoassay and enzyme immunoassay compared for determination of digoxin.

1976 ◽  
Vol 22 (12) ◽  
pp. 2029-2031 ◽  
Author(s):  
L Sun ◽  
V Spiehler
Keyword(s):  
Enzyme Immunoassay ◽  
Correlation Coefficients ◽  
Coefficients Of Variation ◽  
Quantitative Results ◽  
High Control

Abstract Patients' sera were analyzed for digoxin by using two different radioimmunoassays and an enzyme immunoassay. Quantitative results obtained by enzyme immunoassay (I) were compared to results obtained on aliquots of the same sample by the radioimmunoassays (II and III). The correlation coefficients were: I vs. II 0.90, n=108; I vs. III 0.94, n=102; and II vs. III 0.95, n=158. Day-to-day precision (10 days) on a low control (1.3 mug/liter) and a high control 3.0 mg/liter), expressed as coefficients of variation, were: I, 13% and 7.8%, II, 4.0% and 4.7%; and III, 8.9% and 4.2%. Ten digoxin-supplemented samples (0-8 mug/liter) were analyzed by the three methods. Correlation coefficients were: supplemented sample vs. I, O.99; supplemented sample vs. II, 0.97; supplemented sample vs. III, 0.98.

Radioimmunoassay, enzyme immunoassay, spectrophotometry, and gas-liquid chromatography compared for determination of phenobarbital and diphenylhydantoin.

1976 ◽  
Vol 22 (6) ◽  
pp. 749-753
Author(s):  
V Spiehler ◽  
L Sun ◽  
D S Miyada ◽  
S G Sarandis ◽  
E R Walwick ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Enzyme Immunoassay ◽  
Correlation Coefficients ◽  
Gas Liquid Chromatography ◽  
Ultraviolet Spectrophotometry ◽  
Epileptic Patients ◽  
Quantitative Results ◽  
Analytical Procedures

Abstract Sera from epileptic patients were assayed for phenobarbital and diphenylhydantoin by four different analytical procedures. Quantitative results obtained by radioimmunoassay (I) and enzyme immunoassay (II) were compared to each other and to the results obtained on aliquots of the same sample by gas-liquid chromatography (III) and ultraviolet spectrophotometry (IV). For phenobarbital the correlation coefficients were I vs. II, 0.909; I vs. III, 0.947; II vs. III, 0.917; I vs. IV, 0.950; II vs. IV, 0.953. For diphenylhydantoin the correlation coefficients were I vs. II, 0.953; I vs. III, 0.951; II vs. III, 0.957; I vs. IV, 0.862; II vs. IV, 0.898. The immunoassays can be substituted for liquid chromatography or ultraviolet spectrophotometry without changing the resulting clinical interpretations.

Radioimmunoassay, enzyme immunoassay, spectrophotometry, and gas-liquid chromatography compared for determination of phenobarbital and diphenylhydantoin.

1976 ◽  
Vol 22 (6) ◽  
pp. 749-753 ◽  
Author(s):  
V Spiehler ◽  
L Sun ◽  
D S Miyada ◽  
S G Sarandis ◽  
E R Walwick ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Enzyme Immunoassay ◽  
Correlation Coefficients ◽  
Gas Liquid Chromatography ◽  
Ultraviolet Spectrophotometry ◽  
Epileptic Patients ◽  
Quantitative Results ◽  
Analytical Procedures

Abstract Sera from epileptic patients were assayed for phenobarbital and diphenylhydantoin by four different analytical procedures. Quantitative results obtained by radioimmunoassay (I) and enzyme immunoassay (II) were compared to each other and to the results obtained on aliquots of the same sample by gas-liquid chromatography (III) and ultraviolet spectrophotometry (IV). For phenobarbital the correlation coefficients were I vs. II, 0.909; I vs. III, 0.947; II vs. III, 0.917; I vs. IV, 0.950; II vs. IV, 0.953. For diphenylhydantoin the correlation coefficients were I vs. II, 0.953; I vs. III, 0.951; II vs. III, 0.957; I vs. IV, 0.862; II vs. IV, 0.898. The immunoassays can be substituted for liquid chromatography or ultraviolet spectrophotometry without changing the resulting clinical interpretations.

Determination of Methyl 2-Benzimidazolecarbamate in Bulk Fruit Juice Concentrates by Competitive-Inhibition Enzyme Immunoassay

1994 ◽  
Vol 77 (5) ◽  
pp. 1237-1243 ◽  
Author(s):  
Rodney J Bushway ◽  
Barbara E S Young ◽  
Lance R Paradis ◽  
Lewis B Perkins ◽  
Susan K Martin ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Fruit Juice ◽  
Dynamic Range ◽  
Competitive Inhibition ◽  
Correlation Coefficients ◽  
Total Sample ◽  
Coefficients Of Variation ◽  
Limit Of Quantitation ◽  
Liquid Chromatographic

Abstract A polyclonal enzyme immunoassay (EIA) was used to quantitate methyl 2-benzimidazolecarbamate (MBC or carbendazim), a degradation product of benomyl, in bulk fruit juice concentrates. These concentrates are used by industrial producers to prepare juice or juice concentrates sold in supermarkets. Total sample analysis time was less than 18 min without cleanup or 35 min with cleanup. As many as 8 samples can be analyzed simultaneously, with a limit of quantitation of 10 ppb. The assay’s dynamic range ran from 0.5 to 20 ppb MBC but was best from 0.5 to 10 ppb. Intra-assay coefficients of variation (CVs) varied from 4.0 to 13% for standards and from 4.1 to 26% for samples. Inter-assay CVs varied from 4.5 to 47% for standards and 5.6 to 22% for samples. Average recovery of several juice concentrates spiked at 10 to 290 ppb was 97%. A total of 140 juice concentrates comprising 20 different kinds of juice were analyzed by 2 EIA methods and one liquid chromatographic (LC) procedure. MBC-positive samples gave the following correlation coefficients: 0.954 for EIA without cleanup vs LC, 0.956 for EIA with cleanup vs LC, and 0.978 for EIA with cleanup vs EIA without cleanup. MBC concentrations in MBC-positive juice samples ranged from 5 to 2960 ppb.

Enzyme immunoassay of free thyroxin in dried blood samples on filter paper.

1985 ◽  
Vol 31 (5) ◽  
pp. 750-753 ◽  
Author(s):  
N Hata ◽  
K Miyai ◽  
M Ito ◽  
Y Endo ◽  
Y Iijimi ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Filter Paper ◽  
Room Temperature ◽  
Normal Subjects ◽  
Blood Samples ◽  
Double Antibody ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Measurable Range

Abstract We describe a double-antibody enzyme immunoassay for determination of free thyroxin (FT4) in dried blood samples on filter paper, with use of a T4-beta-D-galactosidase complex. The measurable range of FT4 concentration in two 3-mm blood discs, each of which contained about 2.7 microL of blood, was 1.9 to 93 ng/L, as determined by comparison with concentrations of FT4 in known serum standards. FT4 in blood samples dried on filter paper was stable for at least four weeks when kept dry at -20 degrees C, room temperature, or 37 degrees C. The mean coefficients of variation were 7.6% (within assay) and 6.4% (between assays). Results for FT4 by this method correlated well with those for serum determined by radioimmunoassay (r = 0.98). The proposed method can be used to differentiate persons with hyper- and hypothyroidism from normal subjects and those with abnormal concentrations of thyroxin-binding globulin. The procedure seems suited for screening studies.

Determination of Methyl 2-Benzimidazolecarbamate in Wine by Competitive Inhibition Enzyme Immunoassay

1993 ◽  
Vol 76 (4) ◽  
pp. 851-856 ◽  
Author(s):  
Rodney J Bushway ◽  
Lance R Paradis ◽  
Lewis B Perkins ◽  
Titan S Fan ◽  
Barbara E S Young ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Competitive Inhibition ◽  
White Wines ◽  
Average Recovery ◽  
Total Analysis Time ◽  
Coefficients Of Variation ◽  
Limit Of Quantitation ◽  
Total Analysis ◽  
Commercial Kit

Abstract A benomyl polyclonal enzyme immunoassay (EIA) commercial kit was used to quantitate methyl 2- benzimidazolecarbamate (MBC), a degradation product of benomyl in wine. Total analysis time, including sample preparation, was 30 min. As many as 8 samples can be analyzed simultaneously with a limit of quantitation of 5 ppb. The assay logarithmic response was linear from 0.4 to 26 ppb MBC. Intra-assay percent coefficients of variation (%CVs) ranged from 2.4 to 13 for standards and from 7.4 to 21 for actual wine samples. Interassay %CVs varied from 2.6 to 15 for the standards and from 6.9 to 23 for the samples. Average recovery from samples spiked at 10–10 000 ppb was 93% for evaporated red and white wines. MBC was determined in 134 different wines by immunoassay and liquid chromatography (LC). Of these samples, 98 were positive for MBC by both methods with a correlation coefficient (r) of 0.986. The other 36 samples had MBC levels that either were not detectable by either procedure or were below the 10 ppb limit of quantitation for LC. Concentrations of MBC in wine ranged from 5 to 1329 ppb, with the majority ranging from 10 to 300 ppb. Also, a mini-study was conducted using the plate EIA format.

scholarly journals Determination of Citrinin in Barley by Indirect and Direct Enzyme Immunoassay

1996 ◽  
Vol 79 (6) ◽  
pp. 1325-1329 ◽  
Author(s):  
David Abramson ◽  
Ewald Usleber ◽  
Erwin Martlbauer
Keyword(s):  
Enzyme Immunoassay ◽  
Solid Phase ◽  
Polyclonal Antibodies ◽  
Detection Limits ◽  
Keyhole Limpet Hemocyanin ◽  
Buffer Solutions ◽  
Microtiter Plates ◽  
Coefficients Of Variation ◽  
Optimum Extraction

Abstract Polyclonal antibodies against the mycotoxin citrinin were raised in rabbits after immunization with citrinin conjugated to keyhole limpet hemocyanin. The antibodies were used in a competitive indirect enzyme immunoassay (EIA) with citrinin coupled to glucose oxidase as the solid-phase antigen for coating microtiter plates. Detection limits of this indirect EIA for citrinin ranged from 0.4 to 0.8 ng/mL for buffer solutions. Recoveries of citrinin added to ground barley at 100–2000 ng/g ranged from 105 to 112%, with coefficients of variation between 4.5 and 12%. A direct competitive EIA also was established, with citrinin coupled to horseradish peroxidase as the labeled antigen. Detection limits of this direct EIA for citrinin ranged from 2 to 4 ng/mL for buffer solutions. Recoveries of citrinin added to ground barley at 500–2000 ng/g ranged from 108 to 111%, with coefficients of variation between 8.4 and 26.9%. In naturally contaminated barley samples assayed with the indirect EIA, optimum extraction of citrinin was obtained in 30 min, and only one extraction was necessary to recover 72–76% of the analyte.

Determination of Methyl 2-Benzimidazolecarbamate in Blueberries by Competitive Inhibition Enzyme Immunoassay

1992 ◽  
Vol 75 (2) ◽  
pp. 323-327 ◽  
Author(s):  
Rodney J Bushway ◽  
Jasotha Ugabalasooriar ◽  
Lewis B Perkins ◽  
Robert O Harrison ◽  
Barbara E S Young ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Methylene Chloride ◽  
Methanol Extract ◽  
Competitive Inhibition ◽  
Cross Reactivity ◽  
Dietary Risk ◽  
Coefficients Of Variation ◽  
Field Samples ◽  
Dietary Risk Assessment

Abstract A polyclonal enzyme Immunoassay (EIA) method was developed that will quantitate methyl 2- benzlmidazolecarbamate (MBC), the degradation product of benomyl, In blueberries. The entire analysis Is completed within 25 min, and up to 8 samples can be analyzed simultaneously with a detection limit of 18 ppb. The assay response was linear from 0.69 to 22 ppb MBC. Cross-reactivity was confined to the benzimidazole and dicarboxlm- Ide type pesticides. Intra-assay percent coefficients of variation (% CVs) ranged from 3.4 to 18.4 for the standards, and from 3.2 to 20.6 for the samples. Interassay % CVs varied from 7.5 to 22.3 for the standards, and from 7.5 to 22.0 for the samples. Correlation coefficient between immunoassay and liquid chromatography was 0.87 for the methanol extract and 0.98 for the methylene chloride partition of the methanol extract containing 100 mL 1% sodium chloride. None of the 40 field samples analyzed approached the tolerance of 15 ppm (mean of 20 positive samples was 55 ppb). The ability of the EIA to monitor MBC easily and Inexpensively at concentrations far below the tolerance has major implications for current dietary risk assessment methods.

scholarly journals Determination of Egg Proteins in Food Products by Enzyme Immunoassay

2000 ◽  
Vol 83 (1) ◽  
pp. 139-143 ◽  
Author(s):  
Jupiter M Yeung ◽  
W Harvey Newsome ◽  
Michael A Abbott
Keyword(s):  
Detection Limit ◽  
Enzyme Immunoassay ◽  
Polyclonal Antibodies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antigen Binding ◽  
Food Ingredients ◽  
Coefficients Of Variation ◽  
Egg Products ◽  
Whole Egg

Abstract An enzyme-linked immunosorbent assay (ELISA) was developed to determine the presence of egg proteins in foods. The polyclonal antibodies developed were specific to whole egg proteins and did not cross-react with any of the 38 nuts, legumes, or other common food ingredients tested. The concentrations of egg proteins that will inhibit 50% of antibody–antigen binding, IC50, were 3–7 ng/mL, and the linear range was 0.5–62.5 ng/mL. The detection limit was 0.2 ppm for various foods. Recoveries ranged from 67 to 96%. The intra- and inter-assay coefficients of variation in this procedure were 10–13% for ice cream spiked at 0.8 and 1.6 ppm. The ELISA has been applied to ice creams, noodles, pasta, and breads. Egg proteins were identified in all declared egg products, and no false positives were found.

Multicenter Evaluation of Commercially Available Methods for the Immunological Determination of Plasminogen Activator Inhibitor-1 (PAI-1)

1993 ◽  
Vol 70 (05) ◽  
pp. 858-863 ◽  
Author(s):  
P J Declerck ◽  
H Moreau ◽  
J Jespersen ◽  
J Gram ◽  
C Kluft
Keyword(s):  
Correlation Coefficients ◽  
Plasminogen Activator Inhibitor ◽  
Plasma Samples ◽  
Plasminogen Activator Inhibitor 1 ◽  
A Value ◽  
Normal Plasma ◽  
Coefficients Of Variation ◽  
A Minor ◽  
Pai 1

SummaryIn order to evaluate the comparability of data obtained with various available kits for the immunological determination of PAI-1 antigen in plasma and in order to investigate the underlying cause of observed differences, e. g. problems of specificity or of proper calibration of the provided standard, a multicenter study was organised in the framework of the Subcommittee of Fibrinolysis of the Scientific and Standardization Committee.Eight different plasma samples were distributed among 16 laboratories: a pooled normal plasma, NIBSC 87/512, PAI-1 antigen depleted plasma, PAI-1 depleted plasma supplemented with 59 ng/ml active PAI-1 and four different individual plasma samples. A considerable variation in absolute values is observed between the various kits, e.g. in pooled normal plasma a value is found ranging between 7.4 and 28 ng/ml. Harmonization of all data relative to the PAI-l-depleted plasma supplemented with an exact amount of active PAI-1 (59 ng/ml), followed by a statistical analysis using a two way analysis of variance, revealed that 6 out of 7 kits yielded values that were not significantly different with coefficients of variation around 30%. Correlations between the values obtained with these kits yielded slopes between 0.75 and 1.44 with correlation coefficients between 0.973 and 0.999. Values obtained with one kit appeared to be significantly different (even after harmonization) from the other kits (p <0.001 to p <0.05). Comparison of PAI-1 antigen with the PAI activity values in the analysed samples suggests that one kit may deal with a problem of a difference in reactivity between active and latent PAI-1.In conclusion 6 different kits yield results that, only after harmonization, are comparable and do correlate very well. Thus proper calibration of the provided standards may solve the majority of the problems observed with PAI-1 antigen kits. Differential specificity towards different conformational forms of PAI-1, as a consequence of the use of different monoclonal antibodies, is a minor, but a potential problem, that needs to be considered when comparing data obtained with various methods.

New System for Automated Extraction and Simultaneous Determination of Serum Cholesterol and Triglycerides

1975 ◽  
Vol 21 (10) ◽  
pp. 1430-1436 ◽  
Author(s):  
Dorothy F Wease ◽  
Eli S Espinosa ◽  
Yvonne J Anderson
Keyword(s):  
Simultaneous Determination ◽  
Lipid Extraction ◽  
Small Animal ◽  
Correlation Coefficients ◽  
Sample Volume ◽  
Small Sample ◽  
Automated System ◽  
Coefficients Of Variation ◽  
Precision Time

Abstract We describe an automated system for serum lipid extraction and simultaneous determination of cholesterol and triglycerides, with use of continuous-flow equipment. A sample volume of 100 µl of serum is required, and samples are processed at the rate of 20 per hour, which may be increased with slight loss in precision. Time from sample pickup to recorder readout is about 25 min. The system makes use of established colorimetric reactions, and the values obtained agree with ranges currently reported in the literature. Correlation coefficients for results of the automated and manual methods were 0.98 for cholesterol and 0.99 for triglycerides, and the day-to-day coefficients of variation were 1.8% for cholesterol (1 SD = 34 mg/liter) and 3.4% for triglycerides (1 SD = 37 mg/liter). The small sample volume, precision, accuracy, speed, and comparative economy of reagents make this system particularly suitable for multiphasic screening, pediatrics, and small-animal research.

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