Harvard Stem Cell Institute. Stem cells were cultured in 10 cm tissue culture
dishes coated with 5 ml of geltrex (Thermo-Fisher Scientific) diluted in DMEM
(Thermo-Fisher Scientific) with 1:100 ratio for 30 min at 37 °C. Stem
cell culture medium contained mTeSR (Stemcell Technologies) with provided
supplement and normocin (InvivoGen). Stem cells were passaged by detaching with
accutase (Stemcell Technologies) diluted in DPBS (Thermo-Fisher Scientific) at
1:3. After each splitting of stem cells, 10μM Rho-associated kinase
(ROCK) inhibitor (EMD Millipore) was added in medium of re-plated cells. Stem
cell culture medium was replaced daily.