PBMCs (= peripheral blood mononuclear cells) consist mainly of lymphocytes and monocytes. Cryopreservation causes the CD14+ monocytes to significantly lose their ability to attach to TC plastic. Therefore, the use of frozen PBMCs as starting material for DC generation is not possible because the purification step with Monocyte Attachment Medium will not work.
You can either start with cryopreserved CD14+ monocytes (C-12909) or use freshly isolated mononuclear cells or fresh CD14+ monocytes.
Please refer to the Product Manual of C-28050 or our Application Note [Generation of monocyte-derived Dendritic Cells] for the appropriate protocol.