Fig. 3. Aggregation of Saos-2 cells in response to ectopic Pax3 is Ca²⁺ dependent. Phase-contrast images of live Saos-2 cells infected with Ad-Pax3^flag (A) in the presence of normal Ca²⁺-containing media and cultured for three days, or (B) 24 hours after switching the media to low Ca²⁺-containing media. Aggregates of Pax3^flag-expressing cells dissociated after switching to low Ca²⁺-containing media. Bars, 80 µm.