Estimation of DNA fragmentation after induction of MARCO with IPTG. (A) Cells were cultured with IPTG for 36 hours, then high molecular weight DNA was prepared and electrophoresed. Lane 1, MW marker (φX174/HaeIII); 2, wild-type HL-60 cells; 3, 4, and 5, HL-60 transformants NF-1, 2, and 3. (B) High molecular weight DNA was extracted at the indicated periods after IPTG treatment and electrophoresed. Lanes 1 and 14, MW marker; 2, 3, and 4, wild-type HL-60 cells; 5 and 6, mock-transfected HL-60 cells; 7, 8, 9, 10, 11, 12, and 13, NF-1 cells; 2, 5, and 7, no IPTG stimulation; 8, with IPTG for 24 hours; 9, with IPTG for 36 hours; 10, with IPTG for 48 hours; 11, with IPTG for 60 hours; 12, with IPTG for 72 hours; 13, with IPTG for 84 hours; 3 and 6, with IPTG for 96 hours; 4, with RA for 24 hours.