caa a22 4500 605479577 CHVBK 20210128100410.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s10544-015-0023-1 doi (NATIONALLICENCE)springer-10.1007/s10544-015-0023-1 A complementary method to CD4 counting: measurement of CD4+/CD8+ T lymphocyte ratio in a tandem affinity microfluidic system [Elektronische Daten] [Wenjie Li, Yan Gao, Dimitri Pappas] We describe a tandem affinity microfluidic separation that measures the ratio of CD4+/CD8+ T lymphocytes from blood samples. It is performed by injecting 2μL of lysed blood samples at 1800-2700cellsμL-1 into a microfluidic device containing two serially linked affinity regions, followed with a stop flow incubation that captures CD4+/CD8+ T lymphocytes on the corresponding affinity regions. Fluorophore conjugated antibodies are then injected at a controlled shear stress of 1.7dyn cm-2 to label target cells while eluting non-specific cells; and at last the CD4/CD8 ratio is calculated after the cell enumeration. The ratio of CD4+/CD8+ T lymphocytes achieved by our tandem affinity microfluidic system was in close agreement with that performed using conventional flow cytometry (R 2  = 0.97) over a wide range (0.4-2.5) that covered the reference values from immune deficient patients to healthy people. This approach may represent an inexpensive and powerful tool in diagnosis of immunodeficiency disorders including HIV or mycobacterium tuberculosis. Springer Science+Business Media New York, 2015 Tandem affinity microfluidic separation nationallicence Blood cells nationallicence CD4+/CD8 + T lymphocytes nationallicence CD4/CD8 ratio nationallicence Cytometry nationallicence Li Wenjie Department of Chemistry and Biochemistry, Texas Tech University, 79409, Lubbock, TX, USA aut Gao Yan Department of Chemistry and Biochemistry, Texas Tech University, 79409, Lubbock, TX, USA aut Pappas Dimitri Department of Chemistry and Biochemistry, Texas Tech University, 79409, Lubbock, TX, USA aut Biomedical Microdevices Springer US; http://www.springer-ny.com 17/6(2015-12-01), 1-9 1387-2176 17:6<1 2015 17 10544 https://doi.org/10.1007/s10544-015-0023-1 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10544-015-0023-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Li Wenjie Department of Chemistry and Biochemistry, Texas Tech University, 79409, Lubbock, TX, USA aut NATIONALLICENCE 700 1- Gao Yan Department of Chemistry and Biochemistry, Texas Tech University, 79409, Lubbock, TX, USA aut NATIONALLICENCE 700 1- Pappas Dimitri Department of Chemistry and Biochemistry, Texas Tech University, 79409, Lubbock, TX, USA aut NATIONALLICENCE 773 0- Biomedical Microdevices Springer US; http://www.springer-ny.com 17/6(2015-12-01), 1-9 1387-2176 17:6<1 2015 17 10544