Toward the application of raman fiber probe for non invasive cancer diagnosis

Ball-lens hollow Raman Probe (BHRP) and FTIR spectroscopy were used in this study. BHRP was purposed to explore the biochemical alteration in the living animal (in vivo study), mean while FTIR spectroscopy was introduced for clarification of BHRP result. In this study, we focused to the alteration of antisymmetric and symmetric P=O stretching vibration within the azoxymethane-induced colorectal tumor (in mouse). BHRP detected some differences of it due to randomly the edge of BHRP attached the surface of tumor. Meanwhile, the application of FTIR were introduced to differentiate between grade levels of non clinic samples colorectal tumor models at 4 different grades; normal, grade 1, grade2 and grade 3. Detailed investigation of the spectra in the fingerprint region 1800-700 cm^-1 for BHRP and 4000-500 cm^-1 for FTIR revealed some distinct peaks and shoulders, most of which were assignable to wave numbers that shown to represent biochemical changing within the tissue. Differences in peak heights and peak ratios indicated differences in biochemical composition of cancer from different grade level. It was possible to distinguish between their grade. However, all collected colorectal tumor model at different peak was distinguishable, where antisymmetric stretching of CH₂, antisymmetric and symmetric P=O stretching vibration was imaged and mapped clearly. Therefore, BHRP collaborated with FTIR spectral analysis and in combination with calibration curve might be used to distinguish cancer grade within colorectal tumor model tissue. Extension of this method to other cancer type may be of great interest for cancer grade determination.