A Quantitative Relaxometric Version of the ELISA Test for the Measurement of Cell Surface Biomarkers1. Issue 13 (24th February 2014)

• Record Type: Journal Article
• Authors: Alberti, Diego; van't Erve, Mark; Stefania, Rachele; Ruggiero, Maria Rosaria; Tapparo, Marta; Geninatti Crich, Simonetta; Aime, Silvio
• Is Part Of: Angewandte Chemie international edition. Volume 53:Issue 13(2014)
• Page Start: 3488
• Page End: 3491
• Publication Date: 2014-02-24
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201310959
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Quantitative measurement of marker expression in diseased cells is still a topic of considerable interest and different methodologies are currently under intense scrutiny. This work aims at developing an in vitro diagnostic method based on the release of paramagnetic species from relaxometrically "silent" liposomes operated by the action of a phospholipase A₂ (PLA₂) previously targeted to the epitope of interest. The released paramagnetic species causes an increase of the longitudinal water proton relaxation rate proportional to the number of PLA₂ bound to the cell outer surface. The sensitivity of the herein proposed method, named R‐ELISA, was attempted in the detection of folate receptor expression on human ovarian cancer cells by functionalizing PLA₂ with folic acid. Receptor/cell number of 8.3×10⁵ has been measured on IGROV‐1 cells. The R‐ELISA assay can detect nanomolar cell suspension receptor concentrations and has been validated by well‐established spectrofluorimetric procedures.</p> </abstract>