How do you break up cell clumps when passaging?
I find that I only get clumps (with HeLa and similar cell types) if I leave them in Tryple too long. Generally I leave them in room-temp (not hot) Tryple for ~8 minutes, then I angle the dish, lid off, so that I can see the "sheen" of cells on the dish (this happens in the hood, of course). Then I blast the sheen with Tryple using a 1000ul pipetter, which de-adheres the cells. These are generally much less clumped than if I let the Tryple de-adhere the cells.