PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 9436463

Solid phase IL-2-IL-2R alpha assay with time resolved fluorometry.

K Stenroos·P Hurskainen·K Blomberg·C Lindqvist
View original source ↗Export metadata ↓

Abstract

A time-resolved fluorometric, solid phase, receptor ligand interaction assay is described. The assay consists of wells coated with anti-human IL-2 receptor alpha (hIL-2R alpha) monoclonal antibodies (mAb), europium labelled hIL2 (Eu-IL-2) and human recombinant IL-2 receptor alpha subunits expressed in the baculovirus expression vector system (BEVS). In the assay hIL-2R alpha-Eu-IL-2 complexes bind to the solid phase mAb. Receptor bound Eu is dissociated into an enhancer solution where it forms highly fluorescent complexes. The fluorescence is measured in a time-resolved fluorometer. The Kd value calculated from the saturation curve is in good agreement with previously reported values for the low affinity type of IL-2R, making the described assay a simple and nonradioactive alternative for measurement of soluble hIL-2R alpha in biological systems. Furthermore this assay format provides convenient separation of bound ligand from unbound and is therefore suitable for high throughput screenings.

Explore related subjects

EuropiumFluorescent DyesFluorometryHumansImmunosorbent TechniquesInterleukin-2LigandsProtein BindingReceptors, Interleukin-2Recombinant ProteinsJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

K Stenroos, P Hurskainen, K Blomberg, C Lindqvist. 1997. Solid phase IL-2-IL-2R alpha assay with time resolved fluorometry.. https://doi.org/10.1016/s0165-2478(97)02719-3

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1999

Evaluating phosphors for use in X-ray image detectors by the effective performance index (EPI) method: application to Eu3+ activated yttrium based materials.

Phosphor materials used in X-ray image receptors were evaluated by the effective performance index (EPI). EPI describes the dependence of image quality on X-ray to light energy conversion and light diffusion processes. EPI was experimentally determined by means of X-ray luminescence (XLE) and MTF measurements performed on Y2O2S:Eu, Y2O3:Eu, and YVO4:Eu phosphors. The spectral compatibility of these materials with optical detectors (films, photocathodes, photodiodes) was also determined. Highest EPI values were obtained for Y2O2S:Eu-GaAs combination at mammographic energies. All phosphors could be of use in digital X-ray imaging being adequately compatible to silicon photodiodes employed in digital detectors.

Europium↗
PubMed1998

NMR and luminescence studies on the formation of ternary adducts between HSA and Ln(III)-malonate complexes.

At physiological pH and in the presence of an excess of malonate ligand (MAL), the lanthanide ions (Ln=Eu(III), Gd(III) and Tb(III)) are under the form of [Ln(MAL)2(H2O)4]-. Upon addition of human serum albumin (HSA), formation of two different ternary adducts of stoichiometry HSA-Ln(MAL)x(H2O)q (x=2, q=2; x=2, q=4) is detected. On the basis of the reasonable assumption that the binding strength for the two sites on the protein are inversely proportional to the hydration state of the metal ion, stability constants of 4.0.103 M-1 and 3.5.102 M-1 have been evaluated for the system with q=2 and q=4, respectively. Whereas for the stronger binding site it is suggested that the protein provides two or three donor atoms to the coordination cage of the Ln(III) ion, in the case of the weaker binding site it is likely that it corresponds to a simple electrostatic interaction between the negatively charged [Ln(MAL)2(H2O)4]- and positively charged groups on the surface of the protein.

Europium↗
PubMed1998

Europium-activated phosphors for use in X-ray detectors of medical imaging systems.

Three europium-activated phosphors Y2O2S:Eu, Y2O3:Eu, and YVO4:Eu emitting red light were studied to investigate their suitability for radiographic cassettes or digital imaging systems. Screens were prepared from phosphor powders with various coating thicknesses by sedimentation. To assess phosphor light producing efficiency in relation to patient dose, each screen was X-rayed using 40-120 kVp and the number of light photons emitted per X-ray incident was experimentally and theoretically evaluated. Additionally, the capability of the emitted light to sensitize films or to generate electrons in silicon photodiodes used in digital imaging systems was examined. Y2O2S:Eu screens were most efficient in light emission, and when combined with either red sensitive films or Si photodiodes, they were found superior to Y2O3:Eu or YVO4:Eu screens in film grain or electron signal generation. In many cases they were also found superior to terbium-activated phosphors. Provided that several problems related to industrial production (special dyes, reflective backing, crossover effects) are dealt with, those europium-activated screens could be employed in low-tube-voltage radiographic applications.

Europium↗