Figure 1. Observation of micro-sphere in 3D cell culture. OVCAR-3 and OV3R-PTX cells grew in 3D culture for 15 days. (A) Micro-sphere grew in 3D culture without PTX treatment. The pictures were taken by phase-contrast microscopy every 2 days. (B) Quantitative analysis of sphere diameter from A (n = 3 independent experiments). (C) Micro-sphere grew in 3D culture with PTX treatment. Cells were cultured in the presence of 0.1 μM PTX on day 2 and pictures were taken by phase-contrast microscopy every 2 days. (D) Quantitative analysis of sphere diameter from C (n = 3 independent experiments). Representative images are shown. An inverted triangle indicates one-shot treatment. Original magnification, × 100. *, P < 0.05; **, P < 0.01.