Effects of Type IV Collagen and Laminin on theCryopreservation of Human Embryonic Stem Cells

Effects of Type IV Collagen and Laminin on theCryopreservation of Human Embryonic Stem Cells

Sun Jong Kim,a,b Jong Hyuk Park,a,b Jeoung Eun Lee,a Jin Mee Kim,a Jung Bok Lee,a,bShin Yong Moon,c Sung Il Roh,a Chul Geun Kim,b Hyun Soo YoonaaDivision of Stem Cell Biology, Medical Research Center, MizMedi Hospital; bDepartment of Life Science,College of Natural Sciences, Hanyang University; cStem Cell Research Center, Seoul,Korea

Cryopreservation of hESCs
The undifferentiated hESC clumps were harvested for routinepassaging as described above and then transferred to thefreezing medium (90% SR with 10% dimethylsulfoxide[DMSO]; frozen control group) with serial increments ofDMSO (0%, 2%, 4%, 6%, 8%, and 10%). Human type IVcollagen (Sigma, St. Louis) or human laminin (1, 2, and 5μg/ml; Sigma) were added to the freezing medium in eachexperimental group. Thirty to 40 clumps of hESCs wereloaded into a straw (IMV Technologies, L’Aigle Cedex,France) with slow freezing (at the rate of –1°C per minuteuntil –80°C, seeding at –7°C) using a cell freezer (CryoMagic, Miraebiotech, Seoul, Korea) and then stored in liquidnitrogen.