Phenotypic characterization of EU12 subpopulations.

(A) Cell surface immunofluorescence analysis of EU12 cells reveals 4 subpopulations (R1, R2, R3A, and R3B) on the basis of CD34, μHC, and λLC expression. (B) FACS-sorted EU12 cells were counterstained with anti–IL-7R, anti-VpreB, anti-λLC, or anti-δHC mAbs for cell surface profile analysis or fixed and permeabilized before analysis with anti-TdT, μHC, and VpreB Abs.