Abstract
We compared freeze-thaw and bead beating methods for extracting DNA from parasites in oysters and seawater. Bead beating performed better for extracting Cryptosporidium, Giardia, and Toxoplasma in seawater, while freeze-thaw yielded comparable or better detection for Cryptosporidium and Giardia in oysters. This comparison highlights relative strengths and limitations of these methods.