ABT 3 STEP THAW is a medium is designed for the gradual rehydration of glycerol-frozen embryos. Following thawing, embryos should be sequentially immeresed for five minutes in Thaw 1, Thaw 2, and Thaw 3, and then transferred to a suitable holding medium. Most of these media are available individually in 50ml or 20ml EVA mini bags or alternately in 7ml screw-cap vials (5/pk).