CHARACTERIZATION OF HUMAN BREAST BIOPSY SPECIMENS WITH NEAR-IR RAMAN-SPECTROSCOPY

Breast biopsy samples were examined with Raman spectroscopy with laser wavelengths ranging from 406 to 830 nm. A combination of a single-sta ge spectrograph, band reject filter, and CCD detector permitted low la ser powers and minimal risk of sample radiation damage. Spectra of for malin-fixed human tissue revealed Raman features for lipids and carote noids. The best defined lipid feaatures were observed for 782- and 830 -nm laser excitation, while carotenoid features were strongest in the 488-515-nm range due to resonance enhancement. Comparison of the spect ra with those of fatty acid esters revealed that the major lipid compo nent is a derivative of oleic acid. Lipid and carotenoid Raman bands w ere superimposed on a luminescent background which was less prominent at longer laser wavelengths. A compact, portable, diode laser spectrom eter was tested in a clinical setting with fiber optic sampling. The r esults indicate that substantial biochemical information is available from near-IR Raman spectroscopy and the technique may have clinical ap plications.