One‐step collagenase method for zona pellucida removal in unfertilized eggs: easy and gentle method for large‐scale preparation

摘要

PurposeZona pellucida (ZP)‐free eggs are often used for studies such as evaluating the interaction of sperm‐oolemma. To acquire ZP‐free eggs, the most commonly used methods employ acidified Tyrode's solution, enzymatic digestion with a trypsin‐like enzyme, or mechanical methods using micropipettes. However, acidified Tyrode's solution and trypsin‐like enzymes often damage the oolemma, especially when many eggs are treated at once for mass sample analyses. The mechanical method requires skill, and it is time‐consuming to prepare many ZP‐free eggs. Therefore, in this study, to establish an easy, reliable method for preparing ZP‐free eggs, we examined the ZP digestion method originally reported by Zuccotti et al. (J Reprod Fertil 93:515–520, 1991) that uses collagenase.