To define MMTV-Cre expression pattern, I crossed MMTV-Cre mice with Rosa-YFP
reporter mice. Very nice GFP fluorescence signal was seen in ductal trees
of Cre-postive/Rosa-YFP (+/-) mouse mammary glands. I then isolated mammary
epithelial cells using the Stem Cell kit (Collagenase/Hyaluronidase
digestion). No GFP-positive cells were detected using FACS analysis. Can
anyone give some suggestions on how to preserve GFP for FACS? Or can anyone
recommend one good protocol to cut sections from frozen mammary glands? Our
histology core cannot cut the tissues at all. Thanks a lot.