2.3. Karyotype Analysis

The iPSCs were incubated in culture medium containing 0.25 μg/ml colcemid (Invitrogen) for 2 h and were harvested and incubated in hypotonic solution containing 0.4% NaCl (Sigma Corp.) at 37 °C for 20 min. And cells were fixed with a mixture of methanol:acetic acid (3:1, v/v). Slides were aged for 8–12 h at 65 °C and digested with 0.8% trypsin for 15–30 s. Slides were then stained with Giemsa (Gibco Corp.) for 10 min and air-dried.