Sparged, fermentor clutures of a yeast strain (JM43) were aerobically grown on galactose medium (SSG-TEA). At time zero (generation 0) the saprge gas was switched from air to O2-free N2 for 6 generations of anaerobic growth. After six generations, the saprge gas was switched back to air and samples were harvested at 6.13 generations. 30 µg of total RNA was reverse transcribed (Cy3) and hybridized against a reference (Cy5)under the same gas condition, which consisted of a pool of equal masses of RNA from each time point sampled. The data are background-corrected and normalized.