Key native fluorophores analysis of human breast cancer tissues using Gram-Schmidt subspace method.

The native fluorescence (NFL) spectra of human cancerous and normal breast tissues were excited by a selected wavelength of 300 nm to investigate the efficacy of two key fluorophores: tryptophan and reduced nicotinamide adenine dinucleotide (NADH), as cancer biomarkers. The basis spectra of these key fluorophores' subspaces spanned by the corresponding emission spectra are obtained by the Gram-Schmidt method. A support vector machine (SVM) classifier is trained in the subspace to evaluate the sensitivity, specificity, and accuracy. This research demonstrates that the NFL spectroscopy measurements are effective to detect changes of fluorophores compositions in tissues due to the development of cancer.