BCL2 expression in GC B cells. (A) BCL2 in paraffin-embedded reactive tonsil. The tissue section was stained with the avidin-biotin-peroxidase complex (ABC) method. GC B cells are negative for BCL2, whereas MNZ B cells show strong positive staining. Scattered BCL2-positive T cells are seen in the GC. The image was acquired using an Arcturus PixCell II microscope (Mountain View, CA); the image is 200× original magnification (20× objective) and was captured using the PixCell II Image Archiving workstation. (B) BCL2 mRNA expression on Lymphochip and oligonucleotide array. Previously published data revealed low expression of mRNA in GC B cells. (i) Lymphochip analysis.⁹  (ii) Affymetrix Chip analysis.¹⁰  CB indicates centroblast; CC, centrocyte; N, naive B cell; and M, memory B cell. Also note the high expression of BCL2 message in CLL and FL. Only clone 232714 measures truncated transcripts resulting from translocation of the BCL2 gene at the major breakpoint region. (C) BCL2 expression in microdissected germinal center (GC), mantle zone (MNZ), and marginal zone (MGZ) cells measured by real-time PCR (i) and StaRT-PCR (ii). Standard deviation from 3 independent experiments is shown.