A modular cassette and method for separating a composite fluid into at least two component parts thereof during centrifugation is provided. The modular cassette includes a fluid inlet portion, at least one fluid separation portion, at least one media chamber in fluid communication with the fluid separation portion, a fluid collection portion, at least one fluidic channel configured to form a fluid communication between at least two components of the cassette, at least one wax valve including undulating flow channel portions configured to close at least one of the fluidic channels, and at least one heating element configured to actuate the at least one wax valve.