Bioluminescence images of freely moving mouse captured with a cooled-CCD camera.

A: Brightfield view of one Hr-Per1 mouse captured with red LED light and a 50-msec exposure. The sipper tube is shown at left. Also shown are food pellets and the bedding. B & C: Representative images of a freely moving Hr-Per1 mouse acquired without use of an image intensifier or on-chip electron multiplication. Images were taken with 10-sec exposures approximately an hour after providing oral luciferin in the 35-mm dish, visible with the mice. The tail and torso could be captured without blurring when the animal was at rest. Images were selected within a 1-min sequence. Binning was used at the sensor (4 x 4 pixels) to maximize light signal and reduce the read-noise component of images. Intensity shown as pseudocolor are in analog-to-digital units (ADUs) of the camera after bias subtraction. (TIF)