A NEW, NONDESTRUCTIVE METHOD FOR ANALYSIS OF CLINICAL-SAMPLES WITH FT-IR MICROSPECTROSCOPY - BREAST-CANCER TISSUE AS AN EXAMPLE

A new method for infrared analysis of tissues and cells is presented. The method is based on Fourier transform infrared microspectroscopy co upled with attenuated total reflectance. The technique allows spectros copic measurements on the same samples used by pathologists for histop athological evaluation, e.g. stained samples on plain glass slides. Si nce the same specimen can be used as for histopathology, the method do es not require sample preparation or modification. Significantly, the sample is not damaged. Glass absorbs in the infrared and thus has not been used previously in infrared analysis of tissues and cells. Conven tional infrared techniques utilize expensive substrates, such as BaF2 windows and gold coated slides which do not absorb infrared radiation. However, these measurements require special preparation and result in the destruction of the sample. Breast cancer tissues were examined to demonstrate the feasibility and reproducibility of the new method. Li near discriminant analysis was used to discriminate and classify three types of cells: benign, atypical hyperplasia and malignant. It was de monstrated that benign vs. malignant cells were discriminated with 100 % accuracy, benign vs. atypical hyperplasia were discriminated with 10 0% accuracy and malignant vs. atypical hyperplasia were discriminated with an accuracy of 90% and higher.