Beneficial effect of medium with high concentration serum for direct sperm injection into mouse oocytes using a conventional pipette

Although the piezo-electrically driven pipette is much more effective than a conventional pipette for direct sperm injection into mouse oocytes, the piezo-pipette driving unit is expensive and may not be readily accessible to most basic science laboratories. We report here that the inefficiency of the conventional pipette can be improved by performing the operation in a medium with high serum concentration.