Developing Test Methodology to Identify Intrinsic Biomarkers in Biological Models Using Fourier Transform Infrared (FTIR) Spectroscopy

A label-free non-contact test methodology utilizing fiber-optic-based Fourier Transform Infrared (FTIR) spectroscopy has been developed to identify potential biomarkers in cellular systems, which could be associated with disease processes or therapeutic effectiveness. As a biological in-vitro model, different metabolically active cell lines were considered in this study. FTIR absorption spectra of aggressive human glioblastoma (brain cancer) and human melanoma cell lines were compared to normal human skin fibroblasts. A ∼25-cm−1 shift in the absorption peak was observed between normal (∼1153 cm−1) and malignant cell lines (∼1177 cm−1). Furthermore, the addition of 30% H2O2 to normal skin cells produced a similar 25-cm−1 shift in the 1153-cm−1 absorption peak from the normal cells to the 1177 cm−1 found in the malignant cells, thus implicating the presence of large endogenous levels of oxidizers such as H2O2 within the cancer cells which could be responsible in producing this particular peak shift. The observed differences in the absorption spectra between normal and cancer cell lines could potentially be used to identify biomarkers within the absorption wavenumber range of 900–1300 cm−1 (7.7–11.1 μm wavelength range).