This disclosure provides, among other things, a cartridge comprising: (a) a cartridge body comprising a malleable material and having, disposed on a surface of the body, at least one valve body comprising a valve inlet and a valve outlet, each fluidically connected to a fluidic channel; and (b) a layer comprising a deformable material bonded to a surface of the cartridge body and sealing the at least one valve body at points of attachment, thereby forming at least one valve; wherein the at least one valve body is depressed in the cartridge body relative to the points of attachment and wherein the deformable material covering the at least one valve body retains sufficient elasticity after deformation such that in a ground state the valve is open. Also disclosed is an instrument comprising a cartridge interface and a cartridge as described herein engaged with the cartridge interface, wherein (II) the cartridge interface comprises: (A) at least one mechanical actuator, each mechanical actuator positioned to actuate a valve; and (B) at least one motor operatively coupled to actuate a mechanical actuator toward or away from a valve.