Adhesion and spreading
Cell adhesion is the process of cells interacting with and attaching to a surface, a substrate or another cell. Adhesion is a highly regulated process, comprising dynamic cell - cell and cell - extra cellular matrix (ECM) interactions. For mammalian cells it is mediated by specific, complex structures such as selectins, integrins, syndecans, and cadherins, which determine the specificity of such interactions. Moreover, they play an important role in cellular signaling processes by receiving and integrating internal as well as external signals from the environment. Consequently, cell adhesion is of major importance in questions regarding tissue development, inflammation, immunity, cancer and many others. 
 Cell Adhesion: The Molecular Basis of Tissue Architecture and Morphogenesis, Barry M Gumbiner, 1996
Attachment and detachment kinetics
Venneos’ unique measurement principle ‘Cell Adhesion Noise Spectroscopy’ allows the quantification of attachment and detachment kinetics on single cell level. Whenever a cell membrane attaches to the chip’s surface, a signal is detected. Due to the subcellular size of the measuring pixels, the adhesion areas are directly visible in the CAN-Map and can be calculated. The adhesion area is a direct quantification for attachment and detachment kinetics.
For demonstration purposes human dermal fibroblasts were cultured on the CAN-Q Chips. The cells were then treated with increasing concentration of trypsin (untreated control, 50% and 100 %), as well as with FBS-inactivated trypsin (inactivated trypsin). The substances were added after 5 minutes (frame 10). The untreated control (0% trypsin) and the cells exposed to the inactivated trypsin show no detachment, whereas the samples exposed to higher concentrations of trypsin show a dose depended detachment. Due to the high resolution of the CAN-Q Chips cell outgrowth and movement are visible.
For analysis, the CAN-Q Viewer is used. Users can select cells or cell clusters and follow their adhesion area over time. At the moment, the analysis is performed semi-automatic. We are working on algorithms for automated cell detection to simplify the analysis even further. Additionally, shape and polarity of attached cells will be automatically quantified in the future.
The tracking of the detachment due to trypsinization is a common approach to quantify detachment kinetics in microscopy. However, the adhesion area is hardly visible even to well-trained experimenter. Thus, these assays tend to be error prone. CAN Spectroscopy gives an easy to access quantification of these kinetics.
In comparison to conventional impedance spectroscopy, artefacts like different cell amounts are counted out, making experiments more objective and reproducible.