CRITICAL MOLECULE DETECTOR

LASER INDUCED FLUORESCENCE (LIF) CAN SOMETIMES BE USED AS A DIAGNOSTIC DEVICE IN BIOLOGY AND MEDICINE. IN GENERAL, LIF HAS DIFFICULTIES IN RELATING THE FLUORESCENCE SPECTRA TO THE CONCENTRATION OF THE EMITTERS WITHIN THE TISSUE, IN IDENTIFYING DIFFERENT SPECIES, AND IN THE POSSIBILITY OF DESTROYING THE MOLECULES BEING PROBED IF THE WRONG EXCITATION WAVELENGTH IS CHOSEN. MANY OF THE PROBLEMS ASSOCIATED WITH FLUORESCENCE CAN BE ELIMINATED BY THE USE OF RAMAN SCATTERING. RAMAN TECHNIQUES ALLOW THE MEASUREMENT OF MULTIPLE SPECIES EVEN IN AQUEOUS SOLUTIONS WHICH ARE NOT ACCESSIBLE BY INFRARED METHODS BECAUSE OF WATER ABSORPTION. HOWEVER, SPONTANEOUS RAMAN TECHNIQUES GIVE VERY WEAK SIGNALS. SIGNAL ENHANCEMENT IS POSSIBLE BY UTILIZING RESONANCE RAMAN TECHNIQUES. BOTH OF THESE METHODS STILL SUFFER FROM THE FACT THAT SPATIAL AND, TO SOME EXTENT TEMPORAL, INFORMATION IS LOST. THE RESEARCH IS INTENDED TO INVESTIGATE A NON-INVASIVE, REAL-TIME, HIGH RESOLUTION DEVICE FOR THE DETECTION OF ENZYME LEVELS, METABOLITE CONCENTRATIONS, OR OTHER CRITICAL MOLECULES IN SINGLE BIOLOGICAL CELLS. THIS UNIQUE DEVICE IS BASED ON STIMULATED RAMAN SCATTERING AND CAN SIMULTANEOUSLY MEASURE THE CONCENTRATIONS AND TEMPORAL EVOLUTION OF SEVERAL DIFFERENT MOLECULAR SPECIES.