This question is part of the following Ask The Expert session:
If your adherent cells that were adapted to grow in suspension are clumping you might increase the shaking speed a little bit. You can add media that is calcium and magnesium free. Sometimes I have had clumping and when I triturated the cells the clumps they broke up. Since I don’t know your culture conditions it is difficult to help more. One trick is to put the cells in a tall sterile tube like a sterile graduated cylinder and let the clumps settle for a few minutes then use the clump-free upper layer to passage the cells.