PURPOSE: To obtain a method for observing the cell in the early or middle stage of cytokinesis which can not be observed by conventional method.

CONSTITUTION: Variation of chromosome, as well as variation in the profile of a cell, can be observed using a fluorochrome which is bonded to the cell without causing annihilation. Consequently, observation of cytokinesis itself is facilitated and the effectiveness of carcinostatic can be certified in a short time by cultivating cancer cells along with carcinostatic, calculating the number of cytokinetic cells and comparing with a control.