Micropipette aspiration (MPA) is a widely applied method for studying cortical tension and deformability. Based on simple hydrostatic principles, this assay allows the application of a specific magnitude of mechanical stress on cells. This powerful method has revealed insights about cell mechanics and mechanosensing, not only in Dictyostelium discoideum but also in other cell types. In this cha...

The study of cells' dynamical properties is essential to a better understanding several physiological processes. These are directly associated with mechanical parameters experimentally achieved through physical stress. micropipette aspiration essay has proven an accurate and controllable tool apply stress the cell. In this work, we explore numerical modeling two-dimensional cells using active m...

A fluid microplotter that uses ultrasonics to deposit small fluid features has been constructed. It consists of a dispenser, composed of a micropipette fastened to a piece of lead zirconate titanate piezoelectric, attached to a precision positioning system. When an electrical signal of the appropriate frequency and voltage is applied, solution in the tip of the micropipette wicks to the surface...

Key Idea As an indispensable tool for biological investigations into cells, the micropipette allows sampling and injecting fluid across the cell membrane. This operation, however, requires a high dexterity of the operator in order not to damage the membrane and since it is a serial process, it is highly time-consuming if the number of samples grows. To increase the productivity of the sampling ...

Cell adhesion is a fundamental phenomenon vital for all multicellular organisms. Recognition of and adhesion to specific macromolecules is a crucial task of leukocytes to initiate the immune response. To gain statistically reliable information of cell adhesion, large numbers of cells should be measured. However, direct measurement of the adhesion force of single cells is still challenging and t...

PURPOSE To study the feasibility of performing retinal endovascular surgery with a microfabricated needle-based cannulation system at the level of the retinal microvasculature. METHODS A total of 40 retinal vein vessels, and 40 porcine eyes were used, and the eyecups were prepared under an operating microscope. Twenty retinal veins each were pierced with a microfabricated needle having an out...

Bleb-based cell motility proceeds by the successive inflation and retraction of large spherical membrane protrusions ("blebs") coupled with substrate adhesion. In addition to their role in motility, cellular blebs constitute a remarkable illustration of the dynamical interactions between the cytoskeletal cortex and the plasma membrane. Here we study the bleb-based motions of Entamoeba histolyti...

We have developed a technique to directly quantify cell-substrate adhesion force using micropipette aspiration. The micropipette is positioned perpendicular to the surface of an adherent cell and a constant-rate aspiration pressure is applied. Since the micropipette diameter and the aspiration pressure are our control parameters, we have direct knowledge of the aspiration force, whereas the cel...