Phillip Purdy is an Animal Physiologist with the National Animal Germplasm Program.  Goals for his research are new methods for improving the quality of cryopreserved samples (semen, eggs, embryos, DNA, tissue, etc.) that are included in the national repository.  Dr. Purdy investigates new and/or improved methods of cryopreservation for animal germplasm represented within the U.S.  He also develops techniques for evaluating and predicting post-thaw quality based on state-of-art methods including pre-freeze sperm motility, membrane structure, and membrane quality.  Dr. Purdy explores methodologies that increase the in vitro and in vivo fertility of cryopreserved samples.