title: A microfabricated electrical differential counter for the selective enumeration of CD4+ T lymphocytes.
abstract: We have developed a microfabricated biochip that enumerates CD4+ T lymphocytes from leukocyte populations obtained from human blood samples using electrical impedance sensing and immunoaffinity chromatography. T cell counts are found by obtaining the difference between the number of leukocytes before and after depleting CD4+ T cells with immobilized antibodies in a capture chamber. This differential counting technique has been validated to analyze physiological concentrations of leukocytes with an accuracy of ∼9 cells per µL by passivating the capture chamber with bovine serum albumin. In addition, the counter provided T cell counts which correlated closely with an optical control (R(2) = 0.997) for CD4 cell concentrations ranging from approximately 100 to 700 cells per µL. We believe that this approach can be a promising method for bringing quantitative HIV/AIDS diagnostics to resource-poor regions in the world.
authors.affiliation: Department of Electrical and Computer Engineering, Micro and Nanotechnology Laboratory, University of Illinois, Urbana, IL 61801, USA.
authors.forename: Nicholas N
authors.initials: NN
authors.lastname: Watkins
authors.forename: Supriya
authors.initials: S
authors.lastname: Sridhar
authors.forename: Xuanhong
authors.initials: X
authors.lastname: Cheng
authors.forename: Grace D
authors.initials: GD
authors.lastname: Chen
authors.forename: Mehmet
authors.initials: M
authors.lastname: Toner
authors.forename: William
authors.initials: W
authors.lastname: Rodriguez
authors.forename: Rashid
authors.initials: R
authors.lastname: Bashir
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology*; D002417:Cattle; D002452:Cell Count / Q000295:instrumentation / Q000379:methods*; D002457:Cell Extracts; D002469:Cell Separation; D002845:Chromatography; D017097:Electric Impedance; D004912:Erythrocytes / Q000166:cytology; D006801:Humans; D055616:Microtechnology / Q000295:instrumentation / Q000379:methods*; D055620:Optical Phenomena; D015203:Reproducibility of Results
chemical_list: D002457:Cell Extracts