Abstract:
Fourier Transform Infrared (FTIR) spectroscopy is a label free methodology showing promise in characterizing
different types of cell death. Cervical adenocarcinoma (HeLa) and African monkey kidney
(Vero) cells were treated with a necrosis inducer (methanol), novel apoptotic inducers (diphenylphosphino
gold (I) complexes) and positive control, auranofin. Following treatment, cells stained with
annexin-V and propidium iodide were sorted using a Fluorescence Activated Cell Sorter (FACS Aria) to
obtain populations consisting of either viable, necrotic or apoptotic cells. Transmission Electron
Microscopy confirmed successful sorting of all three populations. Four bands were identified which could
discriminate between viable and necrotic cells namely 989 cm 1, 2852 cm 1, 2875 cm 1 and 2923 cm 1.
In HeLa cells viable and induced apoptosis could be distinguished by 1294 cm 1, while four bands were
different in Vero cells namely; 1626 cm 1, 1741 cm 1, 2852 cm 1 2923 cm 1. Principal Component
Analysis showed separation between the different types of cell death and the loadings plots indicated
an increase in an additional band at 1623 cm 1 in dead cells. FTIR spectroscopy can be developed into
an invaluable tool for the assessment of specific types of chemically induced cell death with notably different
molecular signatures depending on whether the cells are cancerous and mechanism of cell death.
