After 2 week acclimation to 12 hr/12 hr light/dark regimen, c57/Bl6 mice were subjected to a 36 hour period of constant darkness. Aortae were subsequently harvested at 4 hour intervals to 48 hours. Duplicate microarrays were hybridized with biotin-labeled probes derived from aorta tissue (6 pooled aortae/timepoint).