Lv 200 system

Tissue explant clock rhythms were investigated by luminescence recording and imaging of 250-μm organotypic slice cultures. Three days after tail vein injections, tissues were dissected at 4–6 h after “lights on” and prepared for luminescence recordings as described [40] (link). For liver explants, median lobes were removed, embedded in low-melting agarose (Invitrogen, Carlsbad, USA), and sectioned with a vibratome (Campden Instruments, Loughborough, UK). Slices were transferred onto culture plate inserts (PICM01250; Millipore, Darmstadt, Germany) in 35-mm petri dishes filled with culture medium. Luminescence recordings were measured in a LumiCycle luminometer (Actimetrics, Evanston, USA) at 32.5 °C. Imaging was done using an Olympus LV-200 system (Olympus, Tokyo, Japan). Analyses were performed using the LumiCycle analysis (Actimetrics) and Prism software packages (GraphPad, La Jolla, USA). Raw data were baseline subtracted with running averages of 24 h (n = 8 per group; for each mouse 3 slices were averaged).