scholarly journals Regioselective Palmitoylation of 9-(2,3-Dihydroxy- propyl)adenine Catalyzed by a Glycopolymer-enzyme Conjugate

Molecules ◽  
2016 ◽  
Vol 21 (5) ◽  
pp. 648 ◽  
Author(s):  
Jana Brabcová ◽  
Jiří Blažek ◽  
Marcela Krečmerová ◽  
Jiří Vondrášek ◽  
Jose Palomo ◽  
...  
Keyword(s):  
Enzyme Conjugate

scholarly journals Enhanced Surveillance of Foodborne Mycotoxins by Immunochemical Assay

1988 ◽  
Vol 71 (6) ◽  
pp. 1075-1081 ◽  
Author(s):  
James J Pestka
Keyword(s):  
Quality Control ◽  
Solid Phase ◽  
Protein Conjugates ◽  
Sample Extract ◽  
Large Numbers ◽  
Wide Range ◽  
Enzyme Conjugate ◽  
Aflatoxin B ◽  
Sampling Procedures ◽  
Instrumental Methods

Abstract Mycotoxins are a chemically diverse group of fungal secondary metabolites with a wide range of toxic effects. Conventional thin-layer and instrumental methods of mycotoxin analysis are time-consuming and make routine safety and quality control screening of these compounds in agricultural commodities difficult. As an alternative, specific polyclonal and monoclonal antibodies have been raised against mycotoxin-protein conjugates and used in sensitive radioimmunoassays (RIAs) and enzyme-linked immunosorbent assays (ELISAs). One of the simplest ELISA approaches involves competition for a solid-phase antibody between a mycotoxin-enzyme conjugate and an unconjugated mycotoxin in the sample extract. ELISAs have been developed for aflatoxins B, and M„ zearalenone, T-2 toxin, and deoxynivalenol, which are highly specific, rapid (10 min), easily adaptable for analyzing large numbers of samples, and directly applicable to assaying methanol-water extracts of a wide range of foods. Several commercial mycotoxin ELISAs using this approach (most typically for aflatoxin B,) are currently being marketed. Since ELISAs will be used in large part by personnel with limited technical expertise, individual kits must be critically evaluated by analytical chemists for suggested sampling procedures, efficiency of extraction, crossreactivity, mycotoxin recovery, assay reproducibility, and product shelf-life prior to routine use in food safety and quality control screening

Quantitative immunoenzymatic assay of human lutropin, with use of a bi-specific monoclonal antibody

1990 ◽  
Vol 36 (1) ◽  
pp. 47-52 ◽  
Author(s):  
G Bugari ◽  
C Poiesi ◽  
A Beretta ◽  
S Ghielmi ◽  
A Albertini
Keyword(s):  
Monoclonal Antibody ◽  
Parental Cell ◽  
Enzyme Linked Immunosorbent Assay ◽  
Parental Cell Line ◽  
Specific Monoclonal Antibody ◽  
Specific Antibodies ◽  
Human Choriogonadotropin ◽  
Enzyme Conjugate ◽  
Capture Antibody ◽  
Immunoenzymatic Assay

Abstract In this immunoenzymatic assay for human lutropin (hLH) we used bi-specific antibodies (BiAbs) obtained from the fusion of two hybridomas producing antibodies to beta-D-galactosidase and hLh. The BiAb complexed with the enzyme beta-D-galactosidase was used as tracer in a double-determinant assay. We compared the assay involving the BiAb (Bi-EIA) with an immunoenzymatic assay (EIA) in which the same capture antibody was used but the tracer was an enzyme-conjugated hLH-specific monoclonal antibody produced by the same parental cell line used to produce the BiAb. The coefficient of correlation (r) between the two assays was 0.979 but the Bi-EIA was more sensitive (detection limits: 0.8 int. units/L for the Bi-EIA, 2.0 int. units/L for the EIA) and more specific (less than 0.04% vs less than 1.2% cross-reactions with human choriogonadotropin). Mean intra- and interassay CVs for the Bi-EIA were 2.9% and 5.9%, respectively. Correlation (r) with an immunoradiometric assay (IRMA, Serono kit) was 0.960, with radioimmunoassay (RIA, Biodata kit) 0.909, and with an enzyme-linked immunosorbent assay (ELISA kit, Specialty Medical Industries Inc.) 0.888, (n = 25). Evidently, bi-specific antibodies can be used successfully in immunoenzymatic assays, and with potentially greater sensitivity and specificity than assay with a traditional antibody-enzyme conjugate.

scholarly journals Determination of Atrazine in Water by Magnetic Particle Immunoassay: Collaborative Study

1996 ◽  
Vol 79 (2) ◽  
pp. 529-537 ◽  
Author(s):  
Mary C Hayes ◽  
Scott W Jourdan ◽  
David P Herzog ◽  
P Barnes ◽  
C Charan ◽  
...  
Keyword(s):  
Detection Limit ◽  
Water Sample ◽  
Magnetic Particle ◽  
Collaborative Study ◽  
Study Data ◽  
Collaborative Studies ◽  
Enzyme Conjugate ◽  
Repeatability And Reproducibility ◽  
The Mean

Abstract A collaborative study was performed to determine mean recovery and precision for analysis of atrazine in drinking and surface waters by immunoassay. The study design was based on the blind duplicate test plan for collaborative studies. Three blank waters (municipal drinking water, well water, and surface water) were spiked at 3 atrazine levels. Two water samples with naturally incurred atrazine loads were also spiked with atrazine at 3 levels. In the enzyme-linked immunoassay method, the water sample is mixed with a pesticide–enzyme conjugate and added to paramagnetic particles with triazine-specific antibodies attached. After separation of antibody-bound atrazine and atrazine–enzyme conjugate from free components, the bound enzyme conjugate catalyzes a reaction producing a colored end product. The color developed is inversely proportional to the original concentration of atrazine in the water sample. Fourteen laboratories participated in the collaborative study. Data were analyzed for repeatability and reproducibility, and average recoveries at the spike levels were calculated. Over the concentration range tested, the mean recovery of atrazine spiked into blank and pesticide-contaminated waters was 104%. Overall RSDRaveraged about 40% for atrazine concentrations near the method detection limit (0.05 μg/L) and about 15% at concentrations above 5 times the detection limit (0.25 μg/L). Corresponding single-analyst RSDr values were 24 and 10%. Recovery and precision for the 3 blank water matrixes and the waters that had been naturally contaminated with atrazine showed no significant differences. The magnetic particle immunoassay

Design of a molecular detection system by a DNA-regulated enzyme conjugate

2009 ◽  
Vol 108 ◽  
pp. S112
Author(s):  
Josui Shimada ◽  
Tatsuo Maruyama ◽  
Noriho Kamiya ◽  
Masahiro Goto
Keyword(s):  
Molecular Detection ◽  
Detection System ◽  
Enzyme Conjugate

Enzyme immunochromatography--a quantitative immunoassay requiring no instrumentation.

1985 ◽  
Vol 31 (7) ◽  
pp. 1144-1150 ◽  
Author(s):  
R F Zuk ◽  
V K Ginsberg ◽  
T Houts ◽  
J Rabbie ◽  
H Merrick ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Matrix Effects ◽  
Biological Fluids ◽  
Test Strip ◽  
Paper Strip ◽  
Assay Result ◽  
Quantitative Immunoassay ◽  
Colored Zone ◽  
Enzyme Conjugate ◽  
Instrumental Methods

Abstract We describe a novel test-strip immunoassay for quantifying drugs in biological fluids. This enzyme immunochromatographic ("immunograph") method combines many features of the enzyme-channeling homogeneous immunoassay with immunochromatography and capillary migration to provide a non-separation, non-instrumental assay for theophylline in which quantification is based on the spatial distribution of enzyme label rather than on the modulation of enzyme activity. Sample antigen and hapten-enzyme conjugate are combined and moved by capillary action up a paper strip on which specific antibody has been immobilized. After color development, the assay result is evaluated by measuring the height of the colored zone on the test strip. Quantification is not a function of enzyme activity, so the method is relatively insensitive to sample matrix effects, enzyme instability, temperature, and incubation timing. Either whole blood or plasma can be used as sample. Results correlate well with those by established instrumental methods. The simple, rapid (15 min), two-incubation protocol is well suited for on-site testing in non-laboratory environments.

scholarly journals Homogeneous Enzyme Immunoassay for Triiodothyronine in Serum

2001 ◽  
Vol 47 (3) ◽  
pp. 569-574 ◽  
Author(s):  
Christina D Karapitta ◽  
Theodore G Sotiroudis ◽  
Athanassios Papadimitriou ◽  
Aristotelis Xenakis
Keyword(s):  
Enzyme Immunoassay ◽  
Glycogen Phosphorylase ◽  
Serum Proteins ◽  
Rabbit Muscle ◽  
Glycogen Phosphorylase B ◽  
Low Concentrations ◽  
Enzyme Conjugate ◽  
High Concentrations ◽  
Treatment Step ◽  
Homogeneous Enzyme Immunoassay

Abstract Background: The concentration of triiodothyronine (T3) in human serum is extremely low and can be determined only by very sensitive methods. We developed a homogeneous enzyme immunoassay for T3 analysis in unextracted serum. Methods: A T3 derivative was conjugated to the −SH groups of glycogen phosphorylase b (GPb) from rabbit muscle. Conjugation caused inhibition of enzyme activity, and the enzyme conjugate was reactivated upon binding of anti-T3 antibody. Activation was blocked by the presence of non-antibody-bound T3; this was the basis for the development of the homogeneous enzyme immunoassay for T3 by determining GPb activity fluorometrically. Results: We used furosemide to block the interaction of T3 with serum proteins with T3-binding sites, avoiding any serum treatment step. T3 was measured in the range 0.3–8 μg/L. T3 values obtained by this assay correlated well with those obtained by a RIA (y = 0.97x − 0.07 μg/L; r = 0.96; n = 92). Within- and between-run imprecision (CV) was 5–9% for normal and high concentrations and 16–20% for low concentrations. Conclusions: Chemical modification of GPb with a T3 derivative allows the development of a simple homogeneous enzyme immunoassay for T3 in unextracted serum.

scholarly journals Plasma clearance of an antibody-enzyme conjugate in ADEPT by monoclonal anti-enzyme: its effect on prodrug activation in vivo

1995 ◽  
Vol 72 (6) ◽  
pp. 1357-1363 ◽  
Author(s):  
GT Rogers ◽  
PJ Burke ◽  
SK Sharma ◽  
R Koodie ◽  
JA Boden
Keyword(s):  
Plasma Clearance ◽  
Prodrug Activation ◽  
Enzyme Conjugate

A Fluorescently Labeled Dendronized Polymer–Enzyme Conjugate Carrying Multiple Copies of Two Different Types of Active Enzymes

2012 ◽  
Vol 134 (28) ◽  
pp. 11392-11395 ◽  
Author(s):  
Andrea Grotzky ◽  
Thomas Nauser ◽  
Huriye Erdogan ◽  
A. Dieter Schlüter ◽  
Peter Walde
Keyword(s):  
Different Types ◽  
Multiple Copies ◽  
Dendronized Polymer ◽  
Enzyme Conjugate
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