1. To generate approx 200 viable eggs for microinjection, use 10 F1 hybrid (e.g., CBA/J X C57BL/6J) females (12-14 g, 4-5 wk old).
2. Inject each mouse ip with 100 |L of 50 IU/mL FSH (5 IU/mouse) between 1000 and 1200 h.
3. Forty-six to 48 h later, inject the same mice with 100 |L of 50 IU/mL hCG (5 IU/ mouse). Immediately place each female with a male stud.
4. On the following morning, check each female for the presence of a copulatory plug. The plug is a creamy white mass of coagulated sperm and protein blocking the vagina. It is normally obvious, but is sometimes deep within the vagina— examine the mouse carefully with a smooth blunt probe.
Was this article helpful?