Differentiation of HaCaT cell and melanocyte from their malignant counterparts using micro-Raman spectroscopy guided by confocal imaging.

Background: Skin cancer is the most common type of cancer in humans. Current techniques for identifying normal and neoplastic tissues are either destructive or not sensitive and specific enough. Raman spectroscopy and confocal imaging may obviate many limitations of existing methods by providing noninvasive, high-resolution, and real-time morphological and biochemical analysis of living tissues and cells.

Methods: We conducted micro-Raman spectroscopy studies on HaCaT cells, melanocytes (MC) and their malignant counterparts squamous cell carcinoma (SCC) and melanoma (MM) cells, respectively. Reflectance confocal imaging is used as guidance for the spectral measurements.

Results: Significant differences were found between the spectra of HaCaT cells and SCC cells, MC cells and MM cells, as well as all normal cells (HaCaT and MC) and all tumor cells (SCC and MM). Approximately 90% sensitivity and specificity was achieved for all the separations that we performed.

Conclusion: Our results demonstrated the robust capability of confocal Raman spectroscopy in separating different cell lines. The acquired Raman spectra of major types of skin cells and their malignant counterparts will be useful for the interpretation of Raman spectra from in vivo skin. We believe it will eventually help diagnosis of skin cancer and other skin disease in clinical dermatology.