Facial Vein Technique:
How to obtain blood samples from the facial vein of a mouse.
Required: 4-5 mm
lancet or 18 gauge needle, small blood collecting tube, clean work surface, and
Not required: Anesthetics
up the mouse by holding its tail. Use the same hand that you prefer to use when handling needles and
pens (the right hand for most people)
the mouse on the wire bars of the cage (or other work surface).
up the mouse so that its nose is pointing back toward the wrist of the restraining
the free hand over the mouse, and scruff it firmly using the thumb and
- NOTE: It is critical that you hold a lot of
skin. Your fingertips should be
touching or almost touching the mouse’s elbows.
know you have enough skin when:
i. The mouse’s eyes bulge out of their sockets (just as if
under anesthesia and totally relaxed)
ii. The mouth is held open
iii. The forelegs stick out to the sides
can tuck the tail between your last two fingers, so that the spine of the
mouse is resting next to your knuckles. If you have enough scruff, this is optional.
should now have the mouse gently and securely restrained in your
non-dominant hand, and be able to pick the mouse up.
the hairless freckle on the side of the jaw.
up the sharp instrument of your choice (lancet or needle) with your free
your sharp instrument so that you are pointing it at the far side of the
mouse’s face, at the base of the far ear or at the base of the far side of
the freckle with the lancet. If
using an 18 gauge needle, go in only up to the depth of the bevel.
drop the sharp into the sharps container and pick up your collection tube.
4-7 drops of blood (maximum amount depends on frequency of bleeding—when
in doubt, contact an RAR veterinarian)
the mouse into its cage when you have obtained your sample. Bleeding should cease immediately.
Q: Mouse pushes
needle away with front foot.
A: Scruff more skin
so front legs can’t move
Q: Mouse arches its
back and scratches with back feet.
A: Scruff more skin;
hold tail securely between fingers.
Q: Mouse doesn’t bleed.
A: Scruff more tightly to hold off vein. Prick freckle just under bone, pointing toward far eye. Try the other side if necessary.
Q: Mouse tongue
and/or lips turn purple.
A: Release mouse, scruff less skin.
Q: Mouse keeps
A: Put gentle pressure on face over prick.
For video clips, see the following commercial video at Medipoint:
(Windows Media) http://www.medipoint.com/html/directions_for_use1.html
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a reference for University of Minnesota investigators, and animal husbandry
and veterinary staff. Drug information and dosages are derived from a variety
of sources and do not necessarily guarantee safety or efficacy. Information
obtained through this site should not be relied upon as professional veterinary
advice. Any medications administered or procedures performed on animals
should only be performed by or under order of a qualified, licensed veterinarian.