Which site is commonly used for non-terminal blood collection in mice?

• A. Cardiac puncture.
• B. Lateral tail vein.
• C. Facial vein.
• D. Saphenous vein.

Answer: (B)

Non-terminal blood collection in mice aims to obtain blood without sacrificing the animal, so the chosen site should be easily accessible, permit repeated sampling, and minimize distress with proper technique. The lateral tail vein fits this best because it’s straightforward to access in awake or lightly restrained mice, supports small-volume draws suitable for routine hematology or pharmacokinetic studies, and avoids surgical procedures or anesthesia when done correctly. Cardiac puncture, by contrast, is a terminal method used only when a final sample is needed at the end of a study. The facial vein and saphenous vein can be used non-terminally, but they’re less consistently preferred in many standard protocols due to smaller or more variable sample yields and the extra technique required. So the lateral tail vein is the most commonly used site for non-terminal blood collection in mice.