Flow cytometric studies using G289-781 MoAb. 697 cells (A) or Namalwa cells (B) were fixed, permeabilized, and incubated with an isotype control antibody (⋅⋅⋅) or G289-781 MoAb without (━) or with (─) peptide 14. Then cells were stained with FITC-conjugated goat antimouse Ig. (C) Cell surface staining of 697 cells using G289-781 MoAb (━) and an isotype control antibody (⋅⋅⋅).