There is a need for an inexpensive syringe that may be conveniently manufactured and preloaded with a single dose of injectable fluid.  Preferably, such a syringe should be unitary and self-contained, comprising all of the elements needed for performing an injection.  In addition, such a syringe would preferably have a built-in safety element in order to reduce the chance of accidental needle sticks and the transfer of blood-borne pathogens such those causing AIDS and hepatitis. Such a safety element should function automatically.  Another desirable safety element would be an indicator to insure the integrity of the preloaded dose.