Human Umbilical Cord OptiTDS* 1 kit^ Kit, Human Umbilical Cord OptiTDS* 1, PrimaCell* Tissue Dissociation System, A mixture of collagenase I, collagenase III, collagenase III, and collagenase IV, Stability: package should be stored at -20 degree Celcius, and effective up to 4 months