Four-part leukocyte differential count based on sheathless microflow cytometer and fluorescent dye assay
Leukocyte differential count is one of the most frequently ordered clinical tests in hospitals. This paper reports a point-of-care test for the leukocyte count by using a microflow cytometer and a fluorescent dye assay. The dye assay relied on fluorescent detection alone to count leukocytes in blood and to identify leukocyte subtypes. By combining the fluorescent assay with a sheathless microflow design, the proposed method achieved a minimal sample volume by eliminating excessive dilution and sheath flow. In this paper, a four-part leukocyte differential count including lymphocyte, monocyte, neutrophil and eosinophil was demonstrated, and the whole test consumed only a small amount of blood (5 μL) and reagents (68 μL in total). The merits of minimal sample volume, long reagent shelf life and portable instrument made this method optimal for point-of-care applications.
Additional Information© 2013 Royal Society of Chemistry. Received 19th September 2012; Accepted 17th January 2013. First published on the web 18 Jan 2013. This work was supported by NSBRI under NASA contract NCC9-58. The authors would like to thank Shijia Chen for the measurement on the scanning microscope. The authors also would like to thank all members of Caltech Micromachining Group for their helpful discussions.
Supplemental Material - c3lc41059e.pdf