Flow cytometric histograms showing distribution of CD19/κ and CD19/λ staining. (A) Histograms showing bright monoclonal κ surface Ig expression. (B) Histograms showing dim monoclonal κ surface Ig expression. (C) Histograms showing a mixed monoclonal κ surface Ig expression and polyclonal B cells with a normal κ-to-λ ratio. (D) Histograms showing a B-cell population with dim CD19 and no surface Ig expression.