After sterile preparation, a small subcutaneous bleb of local anesthetic is placed to the right of the midline. A stab incision thorough the skin and superficial rectus muscle is made with a #15 blade and a teat cannula introduced using sterile technique. A gauze is used to prevent contamination of the sample from small skin vessels. An assistant collects the fluid.
Courtesy of Dr. Amelia Munsterman.