Rapid discrimination of colon cancer cells with single base mutation in KRAS gene segment using laser tweezers Raman spectroscopy.

Laser tweezers Raman spectroscopy (LTRS) as a label-free and non-invasive technology has been proven to be an ideal tool for analysis of single living cells which provides important fingerprint information without interference from surrounding environments. For the first time, LTRS system was successfully employed to examine the colon cancer cells with single base mutation in KRAS gene segment including DKS-8 (KRAS wild-type) and DLD-1 (KRAS mutant-type), HKE-3 (KRAS wild-type) and HCT-116 (KRAS mutant-type). Spectra changes of some vital biomolecules due to the gene mutation state were sensitively recorded by our home-made LTRS system. As a result of the comparison between DKS-8 and DLD-1 cells, an index of 97.5% of correct classification was obtained by combining LTRS with PCA-LDA statistical analysis, while an index of 97.0% of correct classification was achieved between HKE-3 and HCT-116 cells. Moreover, between wild-type cells (DKS-8 and HKE-3) versus mutant-type cells (DLD-1 and HCT-116), the index of correct classification was 81.2%, which was quite encouraging. Our preliminary results showed that the LTRS system coupled with PCA-LDA analysis will have a great potential for further applications in the rapid and label-free detection of circulating tumor cells in liquid biopsy. This article is protected by copyright. All rights reserved.