(A) Representative raw bioluminescence data from FF in black or RF in gray. (B) Phase plot of cultured explants (mean ± SEM), black squares indicate FF, open squares RF. Mean phase data from Per2∷Luc explants was calculated using the time of peak bioluminescence following 24 hours in culture. In the RF group PER2∷LUC bioluminescence demonstrated a significant phase shift in both the lung and soleus explants (*p<0.05, mean ± SEM, Student’s t-test). (C) Representative sections from control soleus (fixed immediately) and one soleus that had been in the LumiCyle for 5 days, stained with H&E, imaged at 20X.