Cell elasticity change as a biomarker for cancer detection: an AFM metrological approach

The cancer diagnosis relies on morphological examination of human cells or tissue samples: this is considered the `gold standard' for the diagnosis of malignancy in any organ system. However, diagnosis based on morphological examination can be difficult, recent studies recognized the cell elasticity changes as a marker for cancer detection. A metrological characterized AFM can be used to make reproducible elasticity measurements on biological samples. In this paper a method to accurately measure a cell elasticity change based on measurement of a stable and homogeneous material is proposed. Nanoindenter characteristics (nanoindenter with pyramidal tip and triangular shape) and indentation parameters (0.1 V as approaching point, 5 um/s as indentation speed and indentation load of 0.4 V) were found feasible for all tested samples. A modal cell elastic modulus of 0.5 kPa for lung tumor cell and a limit AFM measurement reproducibility of 4% was obtained.