Abstract: One or more chemicals are added to a physiological fluid to alter the density and/or shape of cells in the fluid to provide a desired sedimentation rate of the cells. In a preferred embodiment, the chemical to be added is an anticoagulant, preferably ACD.

Abstract: A method for the preparation of an autologous tissue graft composition is disclosed. Bone marrow is harvested from the patient. In one embodiment, the nucleated cells of the bone marrow are subsequently concentrated. Autologous thrombin is purified from a volume of whole blood also taken from the patient. The bone marrow aspirate or bone marrow concentrate is then combined with the purified autologous thrombin to form a coagulated tissue graft material that may be used alone or in conjunction with other graft materials.

Abstract: A method for the preparation of a stable autologous or homologous coagulant from whole blood is disclosed. The direct precipitation of anticoagulated whole blood obviates the need for a plasma isolation step with unexpected results. The autologous or homologous coagulant produced by the method of the present invention demonstrated clotting times equivalent to commercially available bovine thrombin and human thrombin preparations, with improved kinetics of growth factor release from activated platelets over preparations of bovine thrombin.