What is the recommended depth for inserting a needle for IP injection in mice?

What is the recommended depth for inserting a needle for IP injection in mice?

• A. 0.5 cm
• B. 1.0 cm
• C. 0.2 cm
• D. 2.0 cm

Answer: (A)

In intraperitoneal injection in mice, the needle should reach the peritoneal cavity without going too deep. For a typical adult mouse, inserting about 5 millimeters (0.5 cm) lets the tip enter the peritoneal space reliably while minimizing the risk of injuring internal organs like the liver, intestines, or spleen. If you go deeper, around 1 cm or more, the chance of organ injury increases. If you insert too shallowly, around 0.2 cm, the needle may stay in the abdominal wall or muscle and not deliver the substance into the peritoneal cavity. So, approximately 0.5 cm is the best balance between accessing the cavity and avoiding harm.

In intraperitoneal injection in mice, the needle should reach the peritoneal cavity without going too deep. For a typical adult mouse, inserting about 5 millimeters (0.5 cm) lets the tip enter the peritoneal space reliably while minimizing the risk of injuring internal organs like the liver, intestines, or spleen. If you go deeper, around 1 cm or more, the chance of organ injury increases. If you insert too shallowly, around 0.2 cm, the needle may stay in the abdominal wall or muscle and not deliver the substance into the peritoneal cavity. So, approximately 0.5 cm is the best balance between accessing the cavity and avoiding harm.