Cell Characterization

Automation technologies can be used to support research in biological cell manipulation and characterization. Physical characterization of cells can be performed by indenting a cell membrane a fixed amount and recording the corresponding force data. The multi-scale manipulation system at the MSRAL has been outfitted for these types of studies. This research requires the attachment of a pipette with suction capabilities to the manual manipulator along with the integration of a force sensing device to the active manipulator. A study has been conducted on golden whitefish egg cells, which have an outside diameter of 2-3 mm and manipulation and puncture forces on the order of milli-Newtons. Therefore, an off-the-shelf 10g load cell is used for force sensing. Cell indentations of various amounts were produced on the cell by actuating the active manipulator and corresponding forces recorded. This type of force-deflection data can be used to determine stiffness metrics for a particular cell and is useful when comparing different types of cells. Cell relaxation has been observed from examining the force values over time that the cell exerts on the manipulation tool while the cell is indented. This relaxation is modeled with a spring-damper system to further characterize the behavior of the cell. In addition, the effects of salinity and diameter of the stiffness of the cell have also been studied.