Human embryonic stem cells (hESCs) are pluripotent cells capable of differentiation to representatives of all three germ layers. Includes: Isolation of Primary Mouse Embryo Fibroblasts; Thawing and preparing p1 MEF feeder plates; Preparation of MEF- Conditioned Medium (MEF-CM; Microdissection Passaging of hESCs; Bulk passaging of hESC; Cryopreservation of hESCs; Thawing of hESCs; Karyotyping. - [Read Human Embryonic Stem Cell Protocols]