Hello everyone, I¡¯d like to ask two questions: 1. I want to isolate osteoblast from mice, I don¡¯t know which part is better, from long bone, OK? If I use collagenase P to digest bone to remove fibroblast contamination, do you know the appropriate concentration of collagenase P and its digestion time and temperature? 2. When I want to culture epidermal keratinocytes using Sigma Epilife serum-free medium, do I need to coat the dish with collagen, if need, what kind of collagen is OK? Thanks!