Stronger germicidal solutions, such as those containing carbolic acid (phenol) or iodine, either damage living cells or lose their potency in the presence of blood serum. Dakin's solution has neither disadvantage; its solvent action on dead cells hastens the separation of dead from living tissue. Dakin's solution is prepared by passing chlorine into a solution of sodium hydroxide or sodium carbonate. The solution is unstable and cannot be stored more than a few days. The Carrel–Dakin treatment consists of the periodic flooding of an entire wound surface with the solution.