What are non-adherent cells?

Non-adherent or suspension cells are a type of cell culture in which the cells are grown either as single cells or as free-floating clumps suspended in a liquid medium. They are generally grown to a cell density of 2 x 104 to 7.5 x 105 cells/mL in a sterile culture flask or spinner flask and incubated at 37°C with agitation. Unlike adherent cells, the culture vessel does not need to be tissue-culture treated, and dissociation is unnecessary because cells are already free-floating and not attached to a surface, making passaging a lot easier. Common types of non-adherent cells include cell lines that are non-adhesive, cell lines adapted for suspension, hematopoietic cells, and certain tumor tissues.