Contrast microscope images of HCT-116 tumor spheroids formation process. ( A ) HCT-116 cell sheet (Sheet growth = 10 days) on petri dish and ( B – E ) cell sheet was detached by <t>dispase</t> and kept orbital-shaking at 30 rph with dispase doped medium (1/6) for different time. All scale bars are 200 µm. 