Patent ID: 8048375

Claim:
A system for mixing substances comprising: a receptacle having a plurality of interconnected chambers, including a first chamber directly connected to an at least partially compressible second chamber; and an analyzer supporting the receptacle in an operative position and comprising: one or more actuators constructed and arranged to apply a compressive force to the second chamber, the receptacle being positioned in the analyzer so that gravity will draw a fluid from the first chamber into the second chamber when fluid communication is established between the first and second chambers, wherein the analyzer does not include an actuator constructed and arranged to apply a compressive force to the first chamber; an optical detector positioned adjacent to the first chamber and configured to detect an optical signal emitted by the contents of the first chamber; and a controller programmed to control operation of the one or more actuators and to cause the one or more actuators to: (a) apply a compressive force to the second chamber, thereby displacing at least a portion of the contents of the second chamber into the first chamber; (b) remove the compressive force from the second chamber, thereby allowing the displaced contents to flow by gravity from the first chamber to the second chamber without applying a compressive force to the first chamber; and (c) repeat steps (a) and (b) one or more times.