The present invention provides a method of isolating cells or tissues from a culture preparation of the cells or tissues in a medium composition which enables culture of the cells or tissues in suspension, which comprises at least one step selected from the group consisting of the following (A), (B) and (C): (A) passing the culture preparation through a filter having fine pores having a pore diameter of 5-500 μm, (B) adding a chelator to the culture preparation, and (C) diluting the culture preparation with a physiological aqueous solution.