Flow cytometry analysis of TCR V beta 3.1 in PBMC cells compared to an isotype control (blue). Human blood was collected, combined with a hydrophilic polysaccharide, centrifuged, transferred to a conical tube and washed with PBS. 50 ul of cell solution was added to each tube at a dilution of 2x10^7 cells/ml, followed by the addition of 50 ul of isotype control and primary antibody (ab171112) at a dilution of 1:20. Cells were incubated for 30 min at 4ºC and washed with a cell buffer, followed by incubation with a DyLight 488-conjugated goat anti-mouse IgG (H+L) secondary for 30 min at 4ºC in the dark. FACS analysis was performed using 400 ul of cell buffer.