The far red-fluorescent Alexa Fluor® 647 actin conjugate is an important tool for investigating cytoskeleton dynamics in-vivo. This fluorescent conjugate is prepared by labeling the amine residues of polymerized F-actin. After labeling, the conjugates are subjected to depolymerization and subsequent polymerization to ensure that the actin conjugates are able to assemble properly. The labeled actin that polymerizes is then separated from remaining monomeric actin by centrifugation, depolymerized and packaged in monomeric form