thereby forcing droplets 315 out of openings 310 plunger depressor 330 may be automatically operated for example so that when an operator inserts the droplet actuator cartridge into an instrument the active insertion also forces plunger depressor 330 to move plungers through 25 into openings 310 while reservoir plunger assemblies are illustrated in fig3 a 3 b it will be appreciated that in some cases only a single such reservoir plunger assembly is required in other cases more than two reservoir plunger assemblies may be provided prior to forcing plungers 325 into openings 310 protective film 205 may be removed alternatively protective film 205 may be scored or otherwise weakened in regions atop openings 310 so that by applying pressure to plunger depressor 330 droplets 315 may be forced out of openings 310 and through protective film 205 in yet another embodiment an awl scribe needle or other puncturing component may be used to puncture or weaken protective film 205 for example top member 110 may be equipped with an awl scribe or other component configured to puncture or weaken protective film 205 when bottom member 105 and top member 110 are fitted together one or more of droplets 315 may be a fully constituted reagent one or more of droplets 315 may when forced out of opening 310 contact and combine with one or more reagents on surface of bottom member 105 and or top member 110 of cassette 100 to yield a fully constituted reagent in another embodiment droplet 315 constitutes a sample for example a sample may be loaded in reservoir 305 at a point of sample collection and may later.