Briefly, 0.2 µg of pCMV-VSV-G (Addgene, #8454, Watertown, MA, USA), 2 µg of psPAX2 (Addgene, #12260, Watertown, MA, USA), and either 2 µg of pLJM1-EGFP (Addgene, #19319, Watertown, MA, USA) as a control or 2 µg of lentiCRISPR v2 (Addgene, #52961, Watertown, MA, USA) were filled up using 15 µL of Attractene transfection reagent (Qiagen, Hilden, Germany) to a total volume of 300 µL of DMEM without supplements. After 24 h, the culture medium was exchanged for harvest medium. 继续阅读 →