Sinoatrial Node Isolation from Mouse Model: A Procedure to Harvest SA Node from Murine Heart

In the heart, the sinoatrial node or S-A node contains specialized muscle cells that continuously initiate and propagate electric impulses throughout the heart, setting the rate of the heartbeat.

To isolate the S-A node, first, prep an anticoagulant-treated euthanized mouse in the supine position. Anticoagulant treatment helps prevent blood clots for efficient tissue isolation.

Next, make a transverse skin incision followed by cutting the lateral walls of the rib cage to access the contents of the thoracic cavity and expose the underlying heart.

Hydrate the heart with anticoagulant-containing buffer. Remove the lungs along with trachea.

Sever the major blood vessels to excise the heart from the chest cavity. Transfer the excised heart to a buffer-containing silicone-elastomer lined dish for handling the delicate organ.

Secure the apex of the heart. Now, locate the position of the inferior and superior vena cava within the right atrium. Further, identify the location of the S-A node within the tissue patch between the venae cavae.

Remove the apex to drain blood from the heart. Now, separate the atria from the ventricles. Cut along the interatrial septum to remove the left atrium. Lay the right atrium flat and excise the S-A node tissue from it.