RESUMEN
Objective:To methodologically establish the lentivirus granule packaging, concentration and infection against CD34~+ cells from umbilical blood. Methods:The lentivirus system of the 3~(rd) generation was used to produce the virus. Ultrafiltration and ultracentrifugation were employed to concentrate virus. Several treatments were used to improve virus infection including in vitro amplification culture, facilitation of rest cells into cell cycle, promotion of cell adhesion and immobilization during infection, and repeat infection methods. Results:CD34~+ cells were not obviously changed by checking the expression level of CD34 marker on the cell surface after 48 h culture. After two-step concentration, virus titer was increased up to 5.06×10~7/ml, and the infection rate against CD34~+ cells from umbilical blood was increased up to 37.7%.Conclusion:Lentivirus supernatant with over 10~7/ml titer can be obtained using the above methods. Efficient infection against CD34~+ cells from umbilical blood can be achieved.