Actin from cardiac acetone and ether powders is compared to actin from skeletal acetone powder using a modification of an established extraction procedure. The yield of actin from cardiac ether powder is nearly the same as the yield from skeletal acetone powder whereas significantly less actin is obtained from cardiac acetone powder. Sodium dodecyl sulfate polyacrylamide gel electrophoresis shows the actins from each of the sources to be virtually identical in terms of purity and mobility. Molecular sieve chromatography of G-actin demonstrates cardiac actin from ether powder to have identical polymerization and mobility properties as skeletal actin from acetone powder. A simplified procedure, developed for highly purified actin from muscle powder and prepared in a single day is presented. The storage of F-actin at -80 degrees C is also discussed.