Analysis of the TCR Vβ expression by FACS. Lethally irradiated Ly5.1 C57BL/6 recipients received 1 × 10⁶ Ly5.2 Delta1^ext-IgG-cultured cells along with 1 × 10⁵ Ly5.1 BM cells. Blood samples obtained at 3 weeks after HCT were stained with monoclonal antibody against CD3 and TCR Vβ. The percentage of Vβ-positive cells among donor CD3⁺ lymphocytes in mice that received Delta1^ext-IgG-cultured cells (closed bars) and compared with control C57BL/6 mice (open bars) is shown. Data shown are the mean plus or minus SEM of 2 separate experiments (n = 7-10).