Cells that are adherent and sticky must be in single-cell suspension before and during the process of acquisition. Accutase cell detachment solution can be purchase from Innovative Cell Technologies, Sigma, and eBiosciences is an excellent additive to media to keep cells or particles in suspension. The user should test Accutase on their samples before running an actual experiment. Filtering alone is not enough to keep cells from clustering or forming clumps. For samples containing many dead cells, adding DNase to your Flow Buffer is advised.