Actin bundles are the force generating part of a cell, and thus are major players during cell-mechanical processes like cell migration. By cutting individual actin fibers and quantifying the corresponding retraction, the underlying physical properties, like tension and internal forces can be determined. Additionally, by cutting force-generating stress-fibers during cell migration, cell responses, like loss of polarity and reorientation, can be observed.

Movie1: Migrating Keratinocyte. Actin network was stained using life-act (shown in black; inverted LUT). Individual actin bundles were cut to analysis retraction as measure of tension within the actin network.

Setup:

• Zeiss Observer Spinning Disk
• 40x EC Plan-Neofluar NA 1.3 (oil)

Rapp OptoElectronic components:

• UGA-42 Caliburn 355/42 (pulsed laser, 355nm, 1KHz, 42µJ/pulse)

Data from:

Demo data acquired together with Prof. Merkel’s group (ICS-7; Research Center Jülich) at Prof. Großhans’ Lab (Developmental Biochemistry; University of Göttingen).