Skewness of the height distribution in cell topography images is a measure of cell shape

Abstract

The regulation of cell shape is crucial for the functioning of living cells. To analyze cell function, it is therefore important to quantify cell shape. We present an approach for the quantification of vertical cell shape that is based on a statistical analysis of height distributions in topography images such as obtained by scanning probe microscopy. Using scanning ion conductance microscopy (SICM), we found that induced cytoskeletal alterations led to a change from a dome-like toward a fried-egg-like vertical cell shape. This shape change affected a cell’s height distribution and the symmetry of this distribution. We used the third central moment of the distribution, the skewness, as a statistical measure of the distribution’s symmetry and therefore of vertical cell shape. This approach provides an unbiased and fast method for the analysis of vertical cell shape and works even for confluent cell layers.

Nanoscale Electrochemical Mapping

“…There have been interesting recent morphological studies utilizing SICM, [103][104][105][106] including the combination of SICM data with co-located images from super-resolution microscopy (although on separate instruments), 107 which build on the established topographical capabilities of SICM.…”

“…There have been interesting recent morphological studies utilizing SICM, − including the combination of SICM data with colocated images from super-resolution microscopy (although on separate instruments), which build on the established topographical capabilities of SICM. There have also been a number of methodological advances, including new scanning regimes and instrumentation, which have resulted in a diversification in the uses of SICM.…”

Combined High‐Speed Atomic Force and Optical Microscopy Shows That Viscoelastic Properties of Melanoma Cancer Cells Change during the Cell Cycle

“…The modulus scaling parameter and the fluidity are also correlated on a subcellular level on the same master curve as from the population of cells (Figure S6a–d, Supporting Information), in line with recent findings obtained with scanning ion conductance microscopy. [ 48 ] Despite the changes in volume and area, the height skewness [ 49 ] does not change during the cell cycle (Figure S6e, Supporting Information).…”

Mechanics of migrating platelets investigated with scanning ion conductance microscopy

“…Topography images were corrected for tilt and z -offset by a first-order plane fit. 30,33 Platelets were identified as pixels with a height above h = 50 nm. The platelet area A was calculated as the sum of all single pixel areas a i of the platelet, .…”