Upconversion Fluorescence Enables Homogeneous Immunoassay in Whole Blood

Autor: Timo Lövgren, Tero Soukka, Telle Ukonaho, Katri Kuningas, Terhi Rantanen, Henna Päkkilä
Rok vydání: 2007
Předmět:
Zdroj: Clinical Chemistry. 53:145-146
ISSN: 1530-8561
0009-9147
Popis: Many medical conditions are related to alterations in protein or hormone concentrations in blood. These changes are commonly detected with heterogeneous immunoassays that require a separation step before signal measurement. A simple homogeneous assay performable directly in whole blood would be useful in clinical diagnostics, but the performance of homogeneous fluorescence-based immunoassays has been severely limited by autofluorescence and strong absorption of ultraviolet and visible light in whole blood. These problems might be avoided by the use of near-infrared excited upconversion fluorescence. We recently described a novel homogeneous assay method based on upconversion fluorescence resonance energy transfer (FRET). In this method an upconverting phosphor (UCP) is used as a donor and a fluorescent protein or a small-molecular fluorescent dye is used as an acceptor (1)(2). We report here the use of a competitive homogeneous immunoassay for 17β-estradiol (E2) in whole blood as a model to demonstrate the application of upconversion FRET using a near-infrared fluorescent acceptor dye (Fig. 1A⇓ ; and see Fig. 1 in the Data Supplement that accompanies the online version of this Letter at http://www.clinchem.org/content/vol53/issue1). Figure 1. Principle ( A ) and standard curves ( B ) of the upconversion FRET-based competitive homogeneous E2 immunoassay. ( A ), the anti-E2-Fab-coated FCD-546–1 UCP (donor) can bind E2 (analyte) and E2-AF680 conjugate (acceptor). Phosphor emission at …
Databáze: OpenAIRE