Precise determination of elastic modulus of cell using conical AFM probe

The Sneddon formula is conventionally used to calculate the elastic modulus of cell based on atomic force microscope (AFM) experiments. Owing to the disobedience of the formula assumptions, errors exist. Here, the ABAQUS for finite element modeling and analysis was used to simulate the process of compression of cell with a AFM conical probe. It was found that the relative error ranges from 0.094 to 1.455 folds, depending on half angle of the cone, curvature radius at the tip of the cone and the compression depth. By fitting the error data, we proposed a correction factor, which can be multiplied by the Sneddon formula to get a modified formula, providing the more accurate elastic modulus of cell. The experimentally measured elastic moduli of cell and hydrogel are in good agreement with the values obtained using the modified formula. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The Sneddon formula is traditionally used to calculate the elastic modulus of a cell based on AFM experiments. However, errors exist due to formula assumptions. By using ABAQUS for finite element modeling, a correction factor was proposed to modify the formula and provide a more accurate elastic modulus of the cell. Experimentally measured elastic moduli of both cells and hydrogels were in good agreement with values obtained using the modified formula.