The present invention is directed to a multi-compartment medical device for segregated storage and on demand mixing of at least two components and expression of a resulting mixture from the device having a tubular barrel with an opening and a gasket sealing the rear end through which a plunger is axially slidable within the tubular barrel. At least one bypass is provided in the barrel in order to enable fluid movement of the components between front and rear compartments and rear compartments. The present invention is also directed to methods for the use of such devices.
