Objective To rejuvenate the dying UT-7 / EPO cells after resuscitation and optimize their growth density.Methods UT-7 / EPO cells were rejuvanted by changing the media(modified RPMI1640, DMEM and IMDM), adjusting the serum concentration(10%, 15% and 20%), adding various contents(1, 3 and 5 U / ml) of growth factors and coculture with feeder cells derived from mouse peritoneal cavity. The growth curve of cells recovered to normal status was plotted by CCK-8 method, based on which the culture densities of UT-...