Identification of acidic extracellular pH-modulated genes

To investigate the genes that are modulated by acidic extracellular pH, we treated the mouse B16-BL6 cells with acidic medium and then analyzed them comprehensively by cDNA microarray. Serum starved (overnight) cells were further incubated with serum-free growth medium at pH 7.4, 6.8, and 5.9 for 24 h. Total RNA was extracted and analyzed by Whole Mouse Genome Microarray 4x44K.