Fig. 1.

Automated single-cell analysis reveals heterogeneous circadian periods in neighboring cells. (A) Representative bioluminescence images from immortalized mouse ear fibroblast cells carrying the PER2::LUCsv reporter, with three representative cells indicated by arrows. (B) Raw bioluminescence signals of the three representative cells. (C) Baseline-subtracted, detrended, and denoised signals of the three representative cells. (D–F) L-S periodograms for cells 1 to 3. Peak periods are indicated by dashed lines. (G) Fitted cosine trajectories of the three representative cells. Calculated periods: 24.07, 25.51, and 26.98 h for cells 1 to 3, respectively. Note the high agreement with the L-S peak periods in D–F.