Figure 2.

U87MG cells along with primary GB cells growing as monolayers ((a) 40x magnification) and as hanging-drop spheroids (initial day in (b) and final day in (c), 4x magnification). Scale bars are 50 and 100 microns, respectively. The initial day is set to be the first day of cell aggregation in spheroidal shape after seeding, meaning Days 2–4. Accordingly, the final day is the time point where spheroids start to deform and decompose, usually approaching well's borders. This day is Day 14 for most primary spheroids.