The regeneration and division of mouse L-cell karyoplasts.

A technique for efficient cytochalasin-induced enucleation was used to prepare "karyoplasts"--nuclei surrounded by a thin shell of cytoplasm and an outer cell membrane. Methods for estimating the quantity of cytoplasm remaining in karyoplasts indicated that they contained less than 10% of the amount found in whole cells. Procedures for separating karyoplasts from contaminating cytoplasmic fragments and whole cells are also described. Freshly prepared L-cell karyoplasts were unable to adhere to and spread upon a surface. However, after incubation for several days, about 30% of the karyoplasts regained these abilities to some degree. A portion of the regenerating karyoplasts were then observed to divide. These events were confirmed and recorded by time-lapse cinematography. In addition, by culturing karyoplasts under appropriate conditions, clones were isolated.