Captive Maintenance and Venom Extraction of Tityus serrulatus (Brazilian Yellow Scorpion) for Antivenom Production

This protocol describes the method to maintain scorpions for the extraction of high amounts of venom, which is used in the production of neutralizing equine derivative immunoglobulins or anti-venoms. There is a high demand for scorpion anti-venom in tropical countries, which is the keystone for treating human and venom cases. The maintenance procedures reproduce optimal natural conditions, keeping the scorpions in captivity.

Thus, we're considering animal welfare and good laboratory practice. In parallel, venom extraction is based on electrical stimulation in the scorpion tails, with minimal harmful effects on the animals. This protocol enabled us to increase exponentially the number of animals maintained in captivity, ranging from 4, 000 to 20, 000 individuals in 10 years.

At the same time, venom has been extracted sufficiently to immunize horses. to obtain plasma with specifically antibodies, which is the starting material for the manufacturing process that results in around a hundred thousand vials of anti-venom per year. The venom milking procedure is different from others described in the literature in which the telson is removed, thus limiting the number of extractions per animal.

The accumulated experience of the technicians of our facility allow us to extract venom from 200 to 300 animals in around one to one and a half hours without anesthetizing the animals or making other invasive procedures. Begin by preparing the enclosures for housing the scorpions. To smoothen the walls of the polypropylene container acting as an enclosure, place 10 centimeters of self-adhesive plastic tape over its internal surface, as well as on the upper corners of the container.

Then line the floor of the polypropylene container with craft paper, fixed with masking tape on the edges on all sides. Arrange four cardboard trays as vertical substrates on one side of the container with a rigid cardboard sheet between each tray. Place a shallow polypropylene tray containing soaked cotton as a water source on the opposite side of the enclosure.

Place the scorpions in the prepared enclosures and house the containers in the room maintained at 24 degrees Celsius. For complete maintenance, first, remove the scorpions from the water tray. Then using long forceps, remove the water tray from the enclosure.

Place the scorpions in the clean enclosure. Remove all the scorpions left on the enclosure's floor and place them in the clean enclosure. Then remove the remaining live prey from the enclosure.

Remove all the disposable substrates from the enclosure and properly discard them, before sanitizing the reusable items such as water trays and containers with 0.5%hypochlorite solution. To begin, place the scorpions in communal polypropylene containers as enclosures. Calculate the amount of feed according to the energy intake of the scorpions.

Then count the number of cockroaches as prey items. Then apply calcium carbonate with alcohol around the top of the enclosure to prevent cockroaches from escaping the enclosure. Place the cockroaches inside the enclosure for two days.

On the day of venom extraction, count the live scorpions in the enclosure, and using long forceps, transfer them to a glass container. Next, arrange all necessary equipment required for venom extraction on the surface of the airflow cabinet. Plug the electro stimulator power cord into the outlet.

Then turn on the airflow cabinet and electro stimulator. Set the displayed parameters on the electro stimulator machine for venom extraction. Using forceps, hold the metasoma of the scorpion, then immobilize the telson with curved forceps before restraining it with a hand.

After restraint, place the telson in direct contact with an electro stimulator conductor and collect the venom drops into a plastic micro tube. Transfer the telson from the hand to the curved forceps and gently place the scorpion on the bottom of the glass container. After all the scorpions are milked, place them back into the enclosure.

Store the venom at minus 20 degrees Celsius until lyophilization. The venom production of Tityus serrulatus surpasses 80 grams of liquid venom annually, equating to over 13 grams of freeze dried venom. Production indicators such as average venom milked per animal, venom extracted per month, and scorpions extracted per month have shown a positive trend line indicating robust production.