Detection of membrane-bound and soluble antigens by magnetic levitation

• Published in: Lab on a chip Vol. 17; no. 20; p. 3462
• Main Authors: Andersen, Mikkel Schou, Howard, Emily, Lu, Shulin, Richard, Matthew, Gregory, Mark, Ogembo, Gordon, Mazor, Ofer, Gorelik, Pavel, Shapiro, Nathan I, Sharda, Anish V, Ghiran, Ionita
• Format: Journal Article
• Language: English
• Published: England 11-10-2017
• Subjects: Antigens, Surface - analysis; Antigens, Surface - chemistry; Antigens, Viral - chemistry; Blood Cells - chemistry; Blood Cells - cytology; Flow Cytometry - instrumentation; Flow Cytometry - methods; Humans; Immunomagnetic Separation - instrumentation; Immunomagnetic Separation - methods; Interleukin-6 - analysis; Interleukin-6 - chemistry; Mobile Applications; Smartphone
• ISSN: 1473-0189
• DOI: 10.1039/c7lc00402h

Magnetic levitation is a technique for measuring the density and the magnetic properties of objects suspended in a paramagnetic field. We describe a novel magnetic levitation-based method that can specifically detect cell membrane-bound and soluble antigens by measurable changes in levitation height that result from the formation of antibody-coated bead and antigen complex. We demonstrate our method's ability to sensitively detect an array of membrane-bound and soluble antigens found in blood, including T-cell antigen CD3, eosinophil antigen Siglec-8, red blood cell antigens CD35 and RhD, red blood cell-bound Epstein-Barr viral particles, and soluble IL-6, and validate the results by flow cytometry and immunofluorescence microscopy performed in parallel. Additionally, employing an inexpensive, single lens, manual focus, wifi-enabled camera, we extend the portability of our method for its potential use as a point-of-care diagnostic assay.