Most common site for female tubal sterilization is isthmus. Isthmus is the pa of the fallopian tube which is cut or sealed in a tubal ligation or sterilization procedure. In the bipolar electrocoagulation technique, the mid isthmic poion of the tube is grasped and radiofrequency electric current is applied to three adjacent areas and coagulating 3 cm of tube. The Hulka clips are also placed across the mid isthmus. Ref: Maternal and Child Health Nursing: Care of the Childbearing and Childrearing By Adele Pillitteri, page 93