Label-Free Discrimination of Normal and Pulmonary Cancer Tissues Using Multiphoton Fluorescence Ratiometric Microscopy

We performed multiphoton excited autofluorescence and second harmonic generation microscopy for the distinction of normal, lung adenocarcinoma ( LAC), and squamous cell carcinoma (SCC) specimens. In addition to morphological distinction, we derived quantitative metrics of cellular redox ratios for cancer discrimination. Specifically, the redox ratios of paired normal/SCC and normal/LAC specimens were found to be 0.53 +/- 0.05/ 0.41 +/- 0.06 and 0.56 +/- 0. 02/0.35 +/- 0.06, respectively. The lower redox ratios in cancer specimens, indicating an increase in metabolic activity. These results show that the combination of morphological multiphoton imaging along with redox ratio indices can be used for the discrimination of normal and pulmonary cancer tissues