Purification of concentrated hemoglobin using organic solvent and heat treatment

A simple method for obtaining a purified and concentrated hemoglobin (Hb) solution (25 g/100 ml) from human red blood cells has been established. To prevent MetHb formation during the purification procedure, Hb in red blood cells was carbonylated in advance, and then washed red blood cells were mixed with organic solvents such as diethyl ether or dichloromethane for hemolysis and removal of stroma. The Hb solution was isolated by centrifugation (1900g) with the high removal efficiency of phospholipid (> 99.8%). After the solution was heated (60 degrees C, 1 h), the precipitates were removed by centrifugation. The purity of Hb was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Isoelectric focusing and oxygen-binding properties of the obtained Hb solution demonstrated its purity and showed no denaturation of globin. This purification procedure is applicable to large-scale production of the purified Hb.