Opto-fluidic flow analysis for monitoring of immunity levels

We describes the design, development and testing of a cost effective and miniaturized version of a flow analyzer. It is designed to detect fluorescence labeled immunocytes in human blood sample. Availing of advancements in micro fluidics and nanolithographic technique, we fabricated a PDMS based device with integrated micro channels for accommodating the optical fibers. The lensed fibers serves as the waveguides for illumination and collection of laser and scattered signals respectively. As a cell crosses the interrogation point the forward scatter, side scatter and fluorescence are detected. Photomultiplier tubes used in conventional flow cytometers have been replaced here with APDs (avalanche photo detectors) and supplemented with digital signal processing. The prototype was tested with different sized polymer beads as well as the live cells.