Solid-phase radioimmunoassay in antibody-coated tubes for the quantitative determination of tetanus antibodies

1974 ◽  
Vol 160 (1) ◽  
pp. 47-51 ◽  
Author(s):  
S. Bernáth ◽  
E. Habermann
1978 ◽  
Vol 24 (2) ◽  
pp. 339-342 ◽  
Author(s):  
M Steiner ◽  
J L Spratt

Abstract Morphine antibody purified by affinity chromatography was used to develop a solid-phase radioimmunoassay for morphine in polystyrene tubes. The tubes are coated with an appropriate concentration of the purified antibody, rinsed three times with buffered saline, and stored at -15 degrees C. Using tritiated dihydromorphine, we determined competitive morphine binding by difference when the radioactivity in the assay supernates was measured after incubation (1 h, 37 degrees C). Five standard curves, with use of serum equivalents of morphine ranging from 0 to 6 mug/liter, were linear and had a mean correlation coefficient of 0.98. Uncer conditions of the assay, levorphanol was comparable to morphine in its inhibitory effect on binding of labeled dihydromorphine, whereas dextrorphan was essentially inactive. Morphine-3-glucuronide, a major metabolite, is 55-fold less inhibitory in terms of its capacity to displace the radiolabel. We believe that the sensitivity of the technique, coupled with the simplicity of nonseparatory sampling, renders the system suitable for rapid determination of morphine and related compounds in biological fluids.


1999 ◽  
Vol 82 (6) ◽  
pp. 1399-1405 ◽  
Author(s):  
Philemon Manirakiza ◽  
Adrian Covaci ◽  
Paul Schepens

Abstract A rapid and accurate method has been developed for the quantitative determination of capsaicin and its most important analogues, dihydrocapsaicin and nordihydrocapsaicin in chili peppers. These components were extracted with methylene chlo ride and separated from interfering substances with activated charcoal. Further cleanup on Florisil cartridges and elution with ethyl acetate were performed before gas chromatographic with mass spectrometric quantitation. The concentrations found were 440 ± 64 μg/g capsaicin, 81 ± 10 μg/g dihydrocapsaicin, and 11 ± 2 μg/g nordihydrocapsaicin. The mean recovery values for triplicate analysis were between 85-94%.


2002 ◽  
Vol 48 (3) ◽  
pp. 526-532 ◽  
Author(s):  
Marius Ulleland ◽  
Ingar Eilertsen ◽  
Edward V Quadros ◽  
Sheldon P Rothenberg ◽  
Sergey N Fedosov ◽  
...  

Abstract Background: Only cobalamin carried by transcobalamin (holo-transcobalamin) is available for cellular uptake and hence is physiologically relevant. However, no reliable or accurate methods for quantifying holo-transcobalamin are available. We report a novel holo-transcobalamin assay based on solid-phase capture of transcobalamin. Methods: A monoclonal antibody specific for human transcobalamin with an affinity constant >1010 L/mol was immobilized on magnetic microspheres to capture and concentrate transcobalamin. The cobalamin bound to transcobalamin was then released and assayed by a competitive binding radioassay. The quantification of holo-transcobalamin was accomplished using calibrators composed of recombinant, human holo-transcobalamin. Results: The assay was specific for holo-transcobalamin and had a detection limit of 5 pmol/L. Within-run and total imprecision (CV) was 5% and 8–9%, respectively. The working range (CV <20%) was 5–370 pmol/L. Dilutions of serum were linear in the assay range. The recovery of recombinant, human holo-transcobalamin added to serum was 93–108%. A 95% reference interval of 24–157 pmol/L was established for holo-transcobalamin in 105 healthy volunteers 20–80 years of age. For 72 of these sera, holo-haptocorrin and total cobalamin were also determined. Whereas holo-haptocorrin correlated well (r2 = 0.87) with total cobalamin, holo-transcobalamin correlated poorly (r2 = 0.23) with total cobalamin or holo-haptocorrin. Conclusions: The solid-phase capture assay provides a simple, reliable method for quantitative determination of holo-transcobalamin in serum.


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