In-plane detection of fluorescence signals in microfludic lab-on-chip flow cytyometry

Several means of extracting fluorescence signals from flowing cell suspensions in a single plane are examined. Simple microfluidic flow cytometer structures incorporating lateral hydrodynamic focusing were molded in PDMS. Several geometries for embedding optical fibers and custom molded waveguides into the same structure were compared. Improvement in light yield is examined with molded cylindrical lenses and by using channels filled with high refractive index polymers as waveguides.