An apparatus and related method for the optimization of the cryopreservation of various types of cells, including but not limited to hematopoietic and mesenchymal stem and progenitor cells, and endothelial progenitor cells found in normal blood, placental/cord blood, bone marrow or the stromal vascular fraction of adipose tissue. The apparatus for cryopreservation of biological materials in a sterile environment comprises a cryopreservation workstation, a rigid disposable cartridge, and a freezing bag assembly. The apparatus and related method provide for the precise, temperature controlled, homogenously distributed introduction of a cryoprotectant containing dimethyl sulfoxide (DMSO) into a solution containing nucleated cells in a manner that provides a safe increase in osmotic pressure and a controlled release of exothermic heat within the cells as the DMSO penetrates the cell membrane and replaces water molecules prior to the freezing of the cells.