[BioC] detection vs. detection of change

[John Welsh]

I'd like to know whether an intensity signal in a microarray is large enough that, if its gene were downregulated, it would be detected. That is, what proportion of the probes can be "detected" in the target? I'm trying to explore this by dividing random subsets of the experimental (i.e. "R") intensities by a small factor, and asking what proportion of these simulated changes limma detects. Does this sound reasonable? Is there a better way?

John Welsh
Associate Professor
Sidney Kimmel Cancer Center
10835 Altman Row
San Diego, CA 92121
(858) 450-5990 ex.282
jwelsh at skcc.org