A method for the controlled release of calcium from intracellular calcium stores of oocytes, by i) establishing an optimum profile for release of calcium from intracellular calcium stores of oocytes, and ii) applying the following cycles to the oocytes: (A) a pulse perfusion cycle which comprises a step of perfusing with one or more calcium pulse media and a step of subjecting to an electric pulse, and (B) sequences of compensating perfusion cycles which comprise a step of perfusing continuously with a calcium ion-free medium, followed by a step of perfusing with a calcium ion-containing medium; wherein the rhythms of the electric pulses and of the perfusion steps are adjusted in order to reproduce the optimum profile i).