Planar Waveguide: Utility in Amino Acid Detection

A device for the detection of fluorescently labeled nucleic acid sequences immobilized or hybridized to the surface of a planar waveguide has been developed. The device described requires no image gathering or analysis utilities, nor any specially patterned waveguide surface for detection. The system consists of an excitation light source and a photo detector, filters for select fluorescent emissions and a standard glass microscope slide that functions as a planar waveguide (PWG) and assay substrate. The device can discriminate fluorescent DNA products hybridized to a glass based array as effectively as laser based reader instruments, and is a low cost system with a high potential for full automation. The system’s functional parameters are presented along with design schematics of current prototypes. Performance data is also presented showing test results comparable to pre-established fluorescence detection means. Future design goals are also discussed. It is concluded that as a component in telemedicine or other remote medical care strategies, the detection means presented can play a significant role in bringing molecular diagnosis and gene detection to arenas of medical care where it is currently unavailable.