Fig. 2.

Fluorescence-activated cell sorting (FACS) of GFP-positive cells. A: dispersed cells from GFP-negative or GFP-positive mouse proximal small intestine were subjected to FACS after addition of propidium iodide (PI). GFP signal was detected with a 530/30-nm bandpass filter and PI signal with a 575/26-nm bandpass filter. The PI-positive cells (top left) were considered nonviable and excluded. Fluorescent cells selected for sorting are shown in the area outlined. B: histogram showing the percent of GFP-positive cells (0.7% of total cells) that could only be identified when cells were isolated from a GFP-positive mouse duodenum. An equal number of positive and negative cells was collected and used for real-time PCR experiments.