Abstract: A dual-chamber syringe system is disclosed. Critical system oriented elements are disclosed, including plunger valve designs for accurate measurement and true, non-canting displacement; tamper and inadvertent valve actuation indicators, as well as, valve status indicators; anti-reflux construction; novel indicia patterns for dual-chamber syringe operation; structure and method for quality assurance that no gas can be delivered from a proximal chamber of the dual-chamber syringe and a kit for single step dose transfer. In addition, a tapered fitting valve is disclosed. The tapered fitting valve comprises a single molded incompressible, but supple part and a skeletal support whereby the tapered fitting valve is opened by insertion into a tapered fitting. The preferred embodiment of an actuator portion of the valve is elliptical in shape.