Abstract: A method of controlling the concentration of a sample flowing through a microchannel is provided. The method includes flowing a sample carrier fluid from a sample carrier channel and into an upstream portion of a microchannel such that the sample carrier fluid flows from the upstream portion and toward a downstream portion of the microchannel, and flowing a sheathing fluid from a sheathing fluid channel and into the upstream portion of the microchannel such that the sheathing fluid flows from the upstream portion and toward the downstream portion of the microchannel, and generally parallel to the sample carrier fluid. The method further includes detecting a concentration of a sample in the sample carrier fluid in the downstream portion of the microchannel, and adjusting a flow rate of at least one of the sample carrier fluid and the sheathing fluid based upon the detected concentration of the sample.

Abstract: A system for transferring and/or concentrating a sample is provided. The system includes a chamber with a membrane brave positioned within the chamber. An electrode assembly is configured to create an electric field across the membrane to move a charged sample through the chamber such that the sample collects and may concentrate on the membrane. The system may include a plurality of membranes. The system may also include a plurality of microchannels outwardly extending from the channel, where the membrane extends along the plurality of microchannels. Aspects of the invention are also directed to a pipette which may be used to transfer and concentrate a sample on a membrane. Certain embodiments are directed to methods and systems for concentrating a nucleic acid sample.

Abstract: The invention relates to methods and systems for detecting and or analyzing an agent in a sample with a chip having optical components incorporated therein.