EXPERIMENTAL TECHNIQUES
Since these procedures have the potential for injuring the animal - experience becomes the best teacher. New research staff members must learn from an experienced operator and practice under supervision.
Blood samples are difficult to obtain from guinea pigs because there are no accessible veins large enough to easily puncture with a needle. Cardiac puncture is one of few practical means of obtaining blood samples from guinea pigs. With the animal anesthetized and in dorsal recumbency you first prep the left chest including an area inferior to the sternum. If the animal is to survive the bleeding the procedure must be done under aseptic conditions.
Next palpate the heartbeat and insert a 22 gauge needle at a 30 – 45 degree angle just behind the xiphoid process of the sternum. Insert the needle toward the area of the heartbeat and withdraw blood slowly without excessive back pressure. The animal may be returned to its cage when it has recovered from anesthesia and is apparently suffering no ill effects.
