A proposed design for the cryopreservation of intact and adherent human embryonic stem cell colonies.

Recently, it was demonstrated that the application of slow-cooling cryopreservation protocols to adherent human embryonic stem (hES) cell colonies, cultured on matrigel or murine embryonic fibroblast feeder layers, resulted in marked improvement in postthaw viability and reduction in cell differentiation. However, the use of commercially available culture plates for this purpose presents several limitations. Most obviously, these plates are not designed for cryopreservation or to withstand the low temperatures encountered during liquid nitrogen cryopreservation, or both. The physical storage of cryopreserved plates is another consideration, in addition to difficulty in maintaining sterile conditions in liquid nitrogen storage and during the thaw phase in a water bath. Hence, a redesign of the cell culture plate for the cryopreservation of adherent hES cell colonies is proposed. In this model, a culture plate made of synthetic materials resistant to storage at -196 degrees C of liquid nitrogen is designed, with readily attachable screw-cap culture wells that function as a replacement for cryovial storage. The detachable wells facilitate storage and after thawing can easily be reattached to a specially designed holding plate. Currently, there are no commercially available cell culture plates using this design concept. The proposed design is envisioned to facilitate the cryopreservation of intact adherent hES cell colonies that could assist the development of automated systems for handling bulk quantities of cells.