Figure 4

Intensity profile of RB1 exon edges in Jurkat cells. Median log intensities from 27 aligned exons show the edge profile for varying probe lengths (from 20 to 60 nucleotides) and formamide concentrations (see key). As the exons have different sizes, the average probe intensity within each exon is reported by a horizontal line between the two '0' points. The horizontal axis indicates the distance between the 5' end of the probe and the splicing acceptor site on the left side of the figure, and the distance between the 3' end of the probe and the splicing donor site on the right side of the figure. RB1 is expressed at low levels in the cell line K562; nevertheless, these edge profiles (data not shown) are similar but with lower intensities.