Tricaine methanesulfonate (MS-222) solutions are used routinely for clinical and experimental anesthesia of a variety of aquatic organisms. It is commonly accepted that MS-222 alters pH when added to freshwater, and buffering freshwater anesthetic solutions is considered to be the standard of care.
Pharmaceutical grade MS-222 must be buffered with sodium bicarbonate resulting in a pH between 7.0 and 7.5. Two examples of pharmaceutical grade MS-222 are Finquel and Western Chemical’s Tricaine-S. Storage: Powdered and prepared solutions should be stored in a dark brown bottle and kept refrigerated or frozen if possible. Buffered MS-222 treatments were neutralized with sodium bicarbonate to bring the pH of exposure water to that of rearing water (pH ∼7.0). Fish were exposed to MS-222 treatments for 10 minutes after reaching stage 3 anesthetization, or for 10 minutes only for the control treatment (0 mg/L MS-222). Tricaine Methanesulfonate (MS-222) is a popular anesthetic agent used in aquatic species, and is intended for the temporary immobilization of fish, amphibians, and other aquatic, cold-blooded animals. The water should have adequate levels of dissolved oxygen, and appropriate pH, temperature, alkalinity, hardness and salinity for the subjects. MS-222 is an acidic solution. The prepared solution must be buffered to a physiologically appropriate pH before use.
The water should have adequate levels of dissolved oxygen, and appropriate pH, temperature, alkalinity, hardness and salinity for the subjects. MS-222 is an acidic solution. The prepared solution must be buffered to a physiologically appropriate pH before use.
This study examines the potential impacts of 'off-label' use of MS-222 on a model aquatic amphibian, Xenopus laevis (African Clawed Frog). Animals were exposed to an environmentally relevant concentration of nitrogen ammonia, a pollutant commonly found in U.S. waterways, and unbuffered MS-222 in a manner simulating typical field use of the drug.
Anaesthesia is induced in around 2 min, and recovery occurs about 5 min after removal from the anaesthetic solution. The anaesthetic solution should be buffered before use, using sodium bicarbonate. The effects of MS-222 have been evaluated in zebra fish embryos for both short- and long-term (24 h) immobilization (Rombough, 2007).
MS222 or TMS or Tricaine Methanesulfonate is used as an anesthetic and euthanasia agent in fish, amphibians and other cold-blooded animals. This document provides guidance regarding safety for personnel preparing MS222 solutions, the proper usage of the compound, dosages recommended for different applications and proper disposal.