A method for separating at least two discrete volumes of a composite liquid into at least a first component and a second component, comprising centrifuging at least two separation bags containing two discrete volumes of a composite liquid respectively, so as to separate therein the first and second components; transferring at least one fraction of a first separated component from the separation bags into satellite bags connected thereto respectively; detecting a characteristic of a component at determined location in each separation bag; and stopping transferring the at least one fraction of the first component from each separation bag into the first satellite bag connected thereto, upon detection of the characteristic of a component at the determined location.