Two sensitive time-resolved fluoroimmunoassays for cellular fibronectin

1995 ◽  
Vol 41 (9) ◽  
pp. 1283-1287 ◽  
Author(s):  
J Kropf ◽  
A M Gressner

Abstract Two sensitive sandwich-type immunoassays for determination of cellular fibronectin (cFN) in cell culture supernatants and in human plasma were developed. Both assays used a monoclonal antibody with specificity against the EDA sequence, which is characteristic for the cellular form of human and rat FN. Assay 1 involves binding of FN on gelatin-coated microwells followed by reaction with the anti-cFN antibody, whereas in assay 2 the anti-cFN antibody was immobilized first and detection was with an anti-FN antiserum. Time-resolved fluorescence spectrophotometry with measurement of an Eu3+ chelator after dissociation of the solid-phase complexes with urea/sodium dodecyl sulfate in the presence of excess Eu3+ was the detection method. The detection limit of the new assays was between 2.6 and 4.0 micrograms/L cFN. In serial dilution of human plasma samples, parallelism with the calibration curve was obtained over the whole measuring range (12-1000 micrograms/L) with assay 2, whereas assay 1 had deviations of the dilution curves at concentrations > or = 100 micrograms/L. The between-run CVs for assays 1 and 2 were 11.4% and 7.2%, respectively, at a concentration of 200 micrograms/L (median value of 18 experiments). Respective within-series CVs of 4.3% and 4.7% were obtained at the same concentration. The recovery of added cFN from human plasma was between 90% and 96%.

1986 ◽  
Vol 32 (7) ◽  
pp. 1323-1327 ◽  
Author(s):  
H Déchaud ◽  
R Bador ◽  
F Claustrat ◽  
C Desuzinges

Abstract We describe an immunofluorometric assay for prolactin based on lanthanide labeling of a monoclonal antibody and measuring time-resolved fluorescence. In this "sandwich"-type assay, the label (Eu3+) was bound to the second antibody by means of a simple, rapid method involving the anhydride of diethylenetriaminepentaacetic acid. To measure the photoluminescence of europium (or other lanthanides), we have developed a time-resolved fluorometer with a nitrogen laser as the pulsed excitation source. During the assay, the solid-phase antibody immobilized inside a polystyrene tube is incubated with the plasma sample and the second antibody in a one-step procedure. Results for 67 human plasmas correlated well (r = 0.98) with those by an immunoradiometric method.


2020 ◽  
Vol 12 (43) ◽  
pp. 5229-5235
Author(s):  
Lingling Guo ◽  
Zhongxing Wang ◽  
Xinxin Xu ◽  
Liguang Xu ◽  
Hua Kuang ◽  
...  

The developed time-resolved fluorescence immunochromatographic assay can be widely applicable as an ultrasensitive, rapid detection method for FB1 in grains.


1990 ◽  
Vol 36 (3) ◽  
pp. 503-508 ◽  
Author(s):  
I Kahan ◽  
A Papanastasiou-Diamandi ◽  
G Ellis ◽  
S K Makela ◽  
J McLaurin ◽  
...  

Abstract We describe a new "sandwich"-type non-isotopic immunoassay for human somatotropin (GH, growth hormone) in serum. In the assay, GH is captured by a monoclonal antibody immobilized in a white microtiter well and simultaneously reacted with a second biotinylated monoclonal antibody. The degree of binding of biotinylated antibody, which increases with increasing amount of GH in the sample, is quantified by adding streptavidin labeled with the europium chelate of 4.7 - bis(chlorosulfophenyl) - 1.10 - phenanthroline - 2.9 - dicarboxylic acid. The fluorescent complex on the solid phase is then measured by excitation at 337.1 nm (nitrogen laser) and monitoring the emission at 615 nm in a gated fluorometer/analyzer. The proposed procedure has short incubation times (less than 4 h protocol), uses only 25 microL of serum per microtiter well, and gives precise and accurate results. The method was clinically evaluated with samples obtained from pediatric patients undergoing investigation for growth abnormalities and from a patient with acromegaly.


2000 ◽  
Vol 23 (6) ◽  
pp. 947-954 ◽  
Author(s):  
Vivian J.C Willson ◽  
William J.S Lockley ◽  
Andrew Mather ◽  
Jaspal Singh ◽  
Charles M Gilbert ◽  
...  

2016 ◽  
Vol 94 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Elaheh Konoz ◽  
Amir H.M. Sarrafi ◽  
Hamed Sahebi

This method shows a novel, fast, and simple magnetic solid-phase extraction (SPE) and spectrophotometric procedure for preconcentration and determination of ranitidine hydrochloride in human plasma and aquatic samples by using Fe3O4 nanoparticles (NPs) modified by sodium dodecyl sulfate (SDS) as an extractor. The unique properties of Fe3O4 NPs including high surface area and strong magnetism were utilized effectively in the magnetic SPE process. The determination method is based on the SDS-coated Fe3O4 NPs with extracted ranitidine-HCl, which was subsequently monitored spectrophotometrically at λmax = 320 nm. Effects of different parameters influencing the extraction efficiency of ranitidine-HCl including the pH value, amount of SDS, and Fe3O4 NPs, extraction time, desorption solvent, desorption time, and sample volume were optimized. Under optimized conditions, the method was successfully applied to the extraction of ranitidine-HCl from human plasma and aquatic samples. The extraction recovery in human plasma and different matrixes of waters were investigated and values of 89.0%–103.4% were obtained. The calibration graph for the determination of ranitidine-HCl was linear in the range of 0.025–1.50 μg mL−1 with R2 = 0.9946. The limit of detection of the proposed method was 7.5 × 10−3 μg mL−1. The repeatability and reproducibility (relative standard deviation) of the mentioned method were 0.83% and 1.22%, respectively. The experimental results showed that the proposed method was feasible for the analysis of ranitidine-HCl in environmental and biological samples.


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