We started trying to work with centipede venoms in 2014, but we struggled for months to perfect the process of venom extraction. We were used to snakes, with their huge venom yields and long-established procedures for extracting venom. And snakes, of course, have no legs, which actually makes them fairly easy to move around and restrain. Suddenly, we had legs everywhere. Fast, grippy legs. Venom yields were often so low that the liquid would evaporate faster than we could convince ourselves that there was actually something there.
Fortunately, Dr. Eivind Undheim was incredibly generous with his advice on how to extract venom from centipedes, and we were able to develop a procedure that works consistently. The animals are first anesthetized by exposure to CO2 for about two minutes, which keeps them under for three to five minutes. We then restrain them using velcro strips while we apply electrostimulation to the bases of the forcipules. The forcipules are the modified first pair of legs that house the venom glands. We use a commercially available TENS unit to apply low voltage/high frequency elctrostimulation to induce muscle contraction and expel the venom. We use a small spatula to catch the venom and to prevent its mixing with saliva. The video below shows the process after the animal has been anesthetized.