Schematic of the FACS–array procedure for peripheral blood cells.

<p>(<b>A</b>) Schematic of analysis of helper T (Th) cells using the FACS–array procedure for peripheral blood cells, where PBMCs are isolated on a density gradient centrifuge and stained with fluorescence-labeled antibodies (CD4-FITC, CXCR3-APC, and CCR4-PE) and PI for FACS. Total RNA was extracted from each subclass of lymphocytes and subjected to two rounds of cRNA amplification. Synthesized aminoallyl-aRNA samples were labeled with biotin and subjected to microarray analysis. (<b>B</b>) Dot plot imaging of FACS isolation of Th1 and Th2 cells. (1) Lymphocytic subpopulation of PBMCs was selected on the basis of their unique forward and side scatter properties on fluorocytometry. (<b>2</b>) Among the lymphocytes, PI-negative (viable) CD4⁺ Th cells were selected. (3) On the basis of the signal intensity of fluorostaining for the CXCR3 and CCR4 markers, the viable Th cells were separated into two subgroups: CXCR3⁺/CCR4⁻ as Th1 cells and CXCR3⁻/CCR4⁺ as Th2 cells.