cDNA microarray technology is considered one of the most important and powerful tools used to extract and interpret genomic information. The cDNA microarray experiment requires to isolate Ribonucleic Acid (RNA) from both control (known) and experimental (patient) samples. The reverse transcription process is used to convert the extracted RNAs into cDNAs, which are further labeled with fluorescent probes, usually Cy3 for the control and Cy5 for the experimental channel. After subsequent hybridization and washing procedures, cDNA microarrays are scanned at the ~540 nm (green) for the control and ~630 nm (red) for the experimental channel respectively. The scanning procedure produces two 16-bit monochromatic images, which are further registered into a two-channel, Red-Green image. Analysis of cDNA microarray data helps in monitoring the expression levels of thousands of genes simultaneously and provides information relevant to cell activity. Therefore, cDNA microarrays have found applications in toxicological research, gene and drug discovery, and disease diagnosis (e.g., cancer, diabetes, and genetic diseases).