Effect of rat heart conditioned medium in forming mouse ES cell colonies

We reported here a new method of culturing and isolating ES cell colonies from mouse blastocysts. Monolayer culture was made by the heart tissue of a 2-3 weeks postnatal rat, and the conditioned medium (RHCM) were collected from cultures before passage 6. C57BL/6J mouse blastocysts were cultured in RHCM (without feeder layer), while the control group used primary mouse embryo fibroblast (ME) as feeder layer, with LIF added into the medium. After the blastocysts being cultured in RHCM, the rates of embryo attaching, ICM propagating and ES cell colonies forming, were 67%, 93% and 13% respectively. They had no prominent differences with those of the control group. This new method could be useful in establishing mouse ES cell lines simply and effectively.EI02185-1883