Oxygen–hemoglobin dissociation curve the fluid that surrounds it. Hemoglobin (Hb) is the primary vehicle for transporting oxygen in the blood. Oxygen is also carried dissolved in the blood's plasma, but to a much lesser degree. Hemoglobin is contained in red blood cells. Under certain conditions, oxygen bound to the hemoglobin is released into the blood's plasma and absorbed into the tissues. Each hemoglobin molecule has the capacity to carry four oxygen molecules. These molecules of oxygen bind to the iron of the Heme group. The binding of the first oxygen molecule induces a conformational change of hemoglobin that increases the affinity for the
Red blood cell loss, such as prior to an operation. Before blood is given, a small sample of the recipient's blood is tested with the transfusion in a process known as cross-matching. In addition to the transmission of infection, certain types of transfusion reaction. In 2008 it was reported that human embryonic stem cells had been successfully coaxed into becoming red blood cells in the lab. The difficult step was to induce the cells to eject their nucleus; this was achieved by growing the cells on stromal cells from the bone marrow. It is hoped that these artificial red blood cells can eventually