Strategy to amplify CD79b cDNA by RT-PCR and results. (Top) Numbers above the cDNA scheme represent nucleotide (nt) position (with 1 corresponding to the initiation ATG codon). Numbers below the scheme indicate amino acid (Aa) position. Ig domain indicates the extracellular domain, TM the transmembrane, and CYTO the cytoplasmic segment. Positions of the primers are shown by the arrows. (Bottom) RT-PCR analysis showing the two detected fragments: 709 bp and 397 bp. Lanes 1 through 3 and 5 through 8, different CLL cases; lane 4, normal PBL.