Apparatus and methods for providing a field environment filled proximal chamber of a multi-chamber syringe and for filling a prime-free syringe are disclosed. In addition, methods for resetting valves of a multi-chamber syringe without special tools or insertion of foreign objects into the syringe are disclosed. A valve for interfacing with syringes telescopically inserted into a larger syringe and which are generally used as proximal chambers in multi-chamber syringes used in mixing and serial delivery applications is disclosed. Four embodiments of novel resettable valves are disclosed. Also, a syringe assembly for delivering a saline-dose-saline medication sequence is disclosed.