Raman spectroscopy for the diagnosis of unlabeled and unstained histopathological tissue specimens

World J Gastrointest Oncol. 2018 Nov 15;10(11):439-448. doi: 10.4251/wjgo.v10.i11.439.


Aim: To investigate the possibility of diagnosing gastric cancer from an unstained pathological tissue using Raman spectroscopy, and to compare the findings to those obtained with conventional histopathology.

Methods: We produced two consecutive tissue specimens from areas with and without cancer lesions in the surgically resected stomach of a patient with gastric cancer. One of the two tissue specimens was stained with hematoxylin and eosin and used as a reference for laser irradiation positioning by the spectroscopic method. The other specimen was left unstained and used for Raman spectroscopy analysis.

Results: A significant Raman scattering spectrum could be obtained at all measurement points. Raman scattering spectrum intensities of 725 cm-1 and 782 cm-1, are associated with the nucleotides adenine and cytosine, respectively. The Raman scattering spectrum intensity ratios of 782 cm-1/620 cm-1, 782 cm-1/756 cm-1, 782 cm-1/1250 cm-1, and 782 ​​cm-1/1263 cm-1 in the gastric adenocarcinoma tissue were significantly higher than those in the normal stomach tissue.

Conclusion: The results of this preliminary experiment suggest the feasibility of our spectroscopic method as a diagnostic tool for gastric cancer using unstained pathological specimens.

Keywords: Gastric cancer; Histopathological examination; Label-free analysis; Raman spectroscopy.