Drawing Blood from Rats through the Saphenous Vein and by Cardiac Puncture

Summary

Blood draws are necessary in a large number of studies, for example to study the pharmacokinetics profile of a compound. Here, we demonstrate how to draw blood from rats using two techniques: blood draw from the saphenous vein or by cardiac puncture.

Abstract

Drawing blood from rodents is necessary for a large number of both in vitro and in vivo studies. Sites of blood draws are numerous in rodents: retro-orbital sinus, jugular vein, maxillary vein, saphenous vein, heart. Each technique has its advantages and disadvantages, and some are not approved any more in some countries (e.g., retro-orbital draws in Holland). A discussion of different techniques for drawing blood are available ^1-3. Here, we present two techniques for drawing blood from rats, each with its specific applications.

Blood draw from the saphenous vein, provided it is done properly, induces minimal distress in animals and does not require anesthesia. This technique allows repeated draws of small amounts of blood, such as needed for pharmacokinetic studies ^4,5, determining plasma chemistry, or blood counts ⁶.

Cardiac puncture allows the collection of large amounts of blood from a single animal (up to 10 ml of blood can be drawn from a 150 g rat). This technique is therefore very useful as a terminal procedure when drawing blood from the saphenous would not provide a large enough sample. We use cardiac puncture when we need sufficient amounts of serum from a specific strain of rats to grow T lymphocyte lines in vitro ^4-9.

Protocol

Drawing Blood from Rats through the Saphenous Vein and by Cardiac Puncture

Note: All procedures must be approved by your institute's animal care and use committee.

1. Blood draw from the saphenous vein

1. This procedure is performed without anesthesia and requires two persons, one who handles the rat, and one who performs the draw.
2. Make a cone out of a towel or hold the rat with rodent handling gloves, leaving one hind limb exposed.
3. Shave the back of the leg with an electric trimmer until the saphenous vein is visible. Shave a large enough area, so that no hair will come in conta....

Discussion

Drawing blood from the saphenous vein is a convenient way to get small amounts of blood without anesthesia. If repeated sampling is required, check regulations to ensure you do not draw too much blood from one rat.

Drawing blood by cardiac puncture is a convenient way to get large amounts of blood but this is a terminal procedure. The animal must be euthanized at the end of the blood draw.

These techniques (as all techniques on live animals) should be first do.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Needle 20G 1/2	Tool	BD Biosciences	305176	For puncturing the saphenous vein
Microvette 300	Tool	Sarstedt Ltd	20.1308.100	To collect blood from the saphenous vein
Electric trimmer	Tool	Braintree Scientific, Inc.	CLP-32130
Needle 23 G 1	Tool	BD Biosciences	305145	For cardiac puncture
5 ml plastic syringe, slip tip	Tool	Fisher Scientific	14-826-12	For cardiac puncture