Staining of actin filaments in human cell line U-2 OS (HPA070701)
Scale bar represents 10µm
Actin filaments are microfilaments assembled close to the plasma membrane, either as long, fragile bundles of filaments, or as small patches. They make up part of the cellular cytoskeleton, forming a supportive layer just beneath the plasma membrane. Actin filaments end with focal adhesions, which connect the cell to the extracellular matrix. Together they are responsible for both cell movement and morphology. Actin filaments can also serve as avenues for intracellular vesicle transport and make up the midbody ring of the cytokinetic bridge.
Actin filaments are seen either as long and rather distinct bundles of filaments or as small patches of filaments, localized just beneath the plasma membrane.