Preparation of filamentous actin for polarized total internal reflection fluorescence microscopy (polTIRFM) motility assays.

John F Beausang, Yujie Sun, Margot E Quinlan, Joseph N Forkey, Yale E Goldman

Cold Spring Harbor protocols 2012 May 01

filter terms:

Polarized total internal reflection fluorescence microscopy (polTIRFM) can be used to detect the spatial orientation and rotational dynamics of single molecules. polTIRFM determines the three-dimensional angular orientation and the extent of wobble of a fluorescent probe bound to the macromolecule of interest. In this protocol, filamentous actin (F-actin) is polymerized from purified, monomeric actin (G-actin) for use in polTIRFM motility assays in which actin interacts with myosin. The procedures include (1) the preparation of unlabeled F-actin from G-actin; (2) the preparation of F-actin that is sparsely labeled with 6'-IATR (6'-iodoacetamidotetramethylrhodamine); and (3) the preparation of F-actin with a combination of unlabeled, biotinylated, and rhodamine-labeled monomers. Rhodamine-phalloidin actin, also used in polTIRFM assays, can be prepared using a procedure similar to the one for unlabeled actin.

Citation

John F Beausang, Yujie Sun, Margot E Quinlan, Joseph N Forkey, Yale E Goldman. Preparation of filamentous actin for polarized total internal reflection fluorescence microscopy (polTIRFM) motility assays. Cold Spring Harbor protocols. 2012 May 01;2012(5)