Azlactone-functional supports are used to provide cell selection from a mixture such as bone marrow or peripheral blood having a desired target cell population. An azlactone-functional support is derivatized by covalently coupling to the support a biologically active substance that binds the target cells. A mixture containing the target cells is contacted with the derivatized support to bind the target cells to the biologically active substance, and unbound remaining mixture is removed from the support. Bound cells may be eluted from the support to obtain purified target cells. Biologically active substances include antibodies, lectins, proteins, antigens and avidin. The biologically active substance may directly or indirectly bind cells in the mixture. Indirect binding may be through a second, intermediary biologically active substance that is bifunctional. The azlactone-functional support is provided by incorporating an azlactone moiety into a base polymer support that has been selected by prescreening base polymer supports with a cell mixture to identify a base polymer support having minimal nonspecific binding of cells in the mixture.