Fig. 1.

Scan of the first subarray of the microarray slides hybridized with, from left to right, cDNA, 1× SCOTS, 2× SCOTS, and 3× SCOTS from 2 h. (A and B) Cy5 (cDNA) signal only (A) and both Cy5 (cDNA) and Cy3 (genomic DNA) signal (B). The number of genes detected after each round of SCOTS are at the bottom of each column. A set of 100 Typhimurium-specific genes were used to calculate the detection threshold. Genes with signals greater than the median of these 100 genes plus 3 standard deviations were considered to be detected.