Figure 4

Procedure for identifying "informative probes" for the automated scoring system. a) Probes are only informative for a gene if they are downstream of an intragenic restriction site. Other probes may be influenced by transposons located outside the gene, and give an "on" microarray signal (red lines) even if the gene is essential. b) The exception to this rule is if there are no "on" signals anywhere within a restriction fragment. In that case all the probes within the fragment that overlap the gene are informative, since there are no interfering signals.