Patent ID: 8160681

Claim:
An apparatus for measuring the level of a selected molecule in a target sample, comprising: means for illuminating the target with light of a first wavelength F1; means for illuminating the target with light of a second wavelength F2 adjacent to the first wavelength F1; means for receiving from the target emitted light resulting from each of the illuminations at wavelengths F1 and F2 and sampling the intensity of the emitted light at a range of wavelengths including a characteristic Raman emission wavelength Fc associated with the selected molecule and each of the illumination wavelengths; means for developing a first set of sampled intensity values for emitted light resulting from the illumination for wavelength F1, said sample including a value at or near the characteristic emission wavelength Fc associated with the selected molecule and F1, at least one sample adjacent the characteristic wavelength Fc but sufficiently displaced below that wavelength to exclude Raman emissions resulting from the illumination for wavelength F1 and at least one sample adjacent the characteristic wavelength Fc but sufficiently displaced above that wavelength to exclude Raman emissions resulting from the illumination for wavelength F1; means for developing a second set of sampled intensity values for emitted light resulting from the illumination for wavelength F2, said sample including a value at or near the characteristic emission wavelength Fc associated with the selected molecule and F2, at least one sample adjacent the characteristic wavelength Fc but sufficiently displaced below that wavelength to exclude Raman emissions resulting from the illumination for wavelength F2 and at least one sample adjacent the characteristic wavelength Fc but sufficiently displaced above that wavelength to exclude Raman emissions resulting from the illumination for wavelength F2; and means for deriving from ratios of corresponding values in the first and second sets of sampled intensity values an interpolated intensity value for emitted light between the characteristic wavelength Fc associated with each of F1 and F2 that removes the intensity value component due to non-Raman emissions, said interpolated intensity value derived from ratios of corresponding values in the first and second sets representing a measurement of the level of the selected molecule in the target sample.