US Patent:
20090325192, Dec 31, 2009
Inventors:
Hrair Kirakossian - San Jose CA, US
Liping Yu - San Jose CA, US
Douglas A. Petry - San Ramon CA, US
International Classification:
G01N 33/53
G01N 21/00
G01N 33/553
G01N 33/543
US Classification:
435 72, 422 8205, 436164, 436526, 436518
Abstract:
The present invention proves instruments and methods for detecting and/or quantitating an analyte in a fluid sample. The fluid sample is placed in a sample chamber having a small, shallow detection region. The analyte is magnetically labeled using magnetic particles coated with a binding reagent, and is detectably labeled using a fluorescent dye or other detection reagent. The magnetically labeled analyte is concentrated into the detection region using a focusing magnet positioned underneath the sample chamber detection region. Concentrated analyte is measured using excitation optics positioned on top of the sample chamber detection region, adapted to illuminate only the detection region, and detection optics positioned on top of the detection region, adapted to detect only light emitted from the detection region. In a preferred embodiment, the invention provides a simple, rapid assay for measuring the concentration of CD4T cells in a whole blood sample.