Rev. 11/25/97
Rats and mice are obtained from the CLAC and transported to the Procedure room.
In the procedure room set up instruments and pinning board.
Prepare fixative of choice, a volume of about 400 mls is sufficient for perfusion and post fixation of an average adult rat and about 200 mls for a mouse.
Obtain about 50 mls of .75-.90 % buffered saline solution for flush of circulatory system.
50 uls of Heparin (1000 Units/ml) may be added to the 50 mls of saline solution to assist in the flush of circulatory system.
Fill perfusion tube (larger unit on top of plexiglass) and canula with the Ringers/drug solution removing all bubbles from the line by tapping the line thoroughly.
To anesthetize the rodents administer i.p (abdomen injection) about .7- 1.0 cc of Nembutal (Sodium Pentobarbital). Before injecting drug pull back on plunger slightly, if syringe shows blood, this indicates location of needle is in circulatory system. Remove needle and reinsert in a different area.
A pinch to the paw or whisker area eliciting no reflex response indicates sufficient anesthesia to perform perfusion.
Expose thoracic cavity, localize heart and remove any pericardia lining present.
Grasp apex of heart and cut a small opening into the left ventricle with scissors.
Insert cannula into opening and push cannula into right ventricle and up into the area of the aorta. The cannula can be visualized in the aorta if desired.
Clamp the cannula into place with a small hemostat, and then cut a small nick in the right atria to allow blood to flow out of circulatory system.
Start peristaltic pump and set to between 1 and 2 on the dial. When the blood is flowing from the atria and/or the eyes, liver, tongue are clearing of blood, turn off flow and change perfusion line to fixative solution, being careful to not introduce any air bubbles into the line.
Restart the flow with the fixative in the line and after about 5- 10 minutes of fixative flow the animal should be well perfused and ready for dissection.