Northern blot analysis of DARC mRNA expression in human brain tissues. Northern blots containing 2 μg of poly(A+) RNAs from multiple sections of brain (Clontech) were probed with the full-length DARC cDNA (top) and with the 5′ DARC probes (bottom) (see text). Hybridization was performed in QuickHyb solution (Stratagene, La Jolla, CA) at 68°C for 1 hour and washed under stringent conditions according to the manufacturer's instructions. Exposure was 24 hours except for the 5′ probe on amygdala to thalamus samples where exposure was 72 hours. Actin cDNA probe was used to ascertain that an equal amount of mRNA was loaded for each sample (not shown).