Expression profile and quantification of Pax-5, AID, and Id-2 transcripts in normal and CLL B cells. (A) Semiquantitative gene-specific RT-PCRs of Pax-5a, Pax-5/Δ-Ex8, and Id-2 transcripts in normal B cells and in CLL B cells with or without expression of AID. GAPDH was used as cDNA control (B) mRNA transcript amplifications of the Pax-5 and AID genes before and after CD40+IL-4 stimulation in a representative normal healthy donor. (C) Quantification of AID (□), Pax-5a (▴), Pax-5/Δ-Ex8 (), and Id-2 expression transcripts (○) by QRT-PCR normalized to GAPDH mRNA. The gene copy number was calculated with a standard curve generated from serially diluted plasmids containing an amplified fragment of each gene. n = number of study samples.