M. Therneau 's Description of probes2.pdf or probes2.ps
or probes2.ps contains one figure for each of the spiked in
genes, one plot for each probe, for the Affymetrix U95A spike
in experiment. The .cel files for each chip were scaled to a
common mean, other than that no normalization has been done.
Black are PM and red are MM probes.