Patent ID: 7189573

Claim:
A method for determining the presence of at least one biological analyte that may be present in a liquid sample comprising: providing an apparatus for testing fluid samples that includes a flow cell with a measurement chamber, a monitor device that directly monitors the progress of a sample and a reagent flow in the measurement chamber, a light source that produces an incident beam directed to measurement chamber; and a sensor positioned to receive an output beam from the flow cell; introducing the liquid sample into the flow cell; directly monitoring the progress of fluid flow within the measurement chamber and at least another section of the flow cell and sense multiple events in the flow cell; detecting changes in the measurement chamber, and in response to the changes determine if there is a sufficient amount of at least one of sample and reagent in the measurement chamber; and providing in a real time basis a sensing of a sample or a reagent without relying on information that originates outside the flow cell.