Which experimental method for measuring cell adhesion is difficult to quantify the force detaching the cells?

The sedimentation-detachment assay measures cell adhesion based on the principle of allowing cells to sediment over a certain period and then assessing the number of cells that remain attached to a substrate. While it can provide information about the overall adhesion properties of the cells, it does not directly measure the force required to detach the cells. Because the method relies on the observation of cell numbers rather than quantifying the actual forces involved in cell detachment, it fails to offer a clear and precise metric for the force maintaining the cell attachment.

In contrast, methods like centrifugation and shear flow assays are designed to apply specific forces to cells and quantitatively assess how strong the adhesion is by measuring the forces necessary to detach the cells. These techniques can provide more precise and quantifiable data regarding the strength of cell adhesion. Therefore, the sedimentation-detachment assay is recognized as less effective in quantifying the forces that keep cells attached compared to those methodologies that measure detachment forces directly.