CREW’s CryoBioBank® is a cryostorage facility for long-term germplasm storage of seeds and tissues of endangered plants. Cryopreservation uses liquid nitrogen (LN) (-196oC/320oF) to preserve living tissues in a stable condition for long periods of time. It is thought that LN storage can preserve tissues for decades or longer. CREW’s CryoBioBank® holds several collections: Regional Seed Bank – Seeds of species listed as endangered, threatened or potentially threatened in Ohio, Kentucky and Indiana. Ferns-International Pteridophyte Bank – Spores and tissues of ferns and related species. CREW researchers have developed procedures for storing both brown and green spores, as well as gametophytes and shoot tips of ferns. Mosses-International Bryophyte Bank – Tissues (gametophytes) and spores of mosses and liverworts. Endangered Plant Tissue Bank – Shoot tips from the tissue culture lines in the Endangered Plant Propagation Program. Experimental Collection – Non-endangered seeds, shoot tips and other tissues that are in long term storage to evaluate their viability over extended storage times. Samples of these are thawed periodically for evaluation. In some cases duplicate samples are being stored at –20 degrees Celsius and at 4 degrees Celsius to compare viability over time at these temperatures and in liquid nitrogen.