As stated,the doubling time for my sf9 cells were increased:the cells were seeded at the density of 106/ml and three days later,it only reached 2*106/ml with higher than 90% viability.The cells were newly thawed and subcultured for 4-5 passages.The conditions,including temperature(27oC) and shaking speed(120rpm)followed exactly my previous experiment,which gave good results.The same frozen stock were thawed before and they grown very well. Can anyone have any ideas?