43A METHOD FOR THE PREPARATION OF A HEAT STABLE OXYGEN CARRIER-CONTAINING PHARMACEUTICAL COMPOSITION5 ABSTRACT OF THE DISCLOSUREA highly purified and heat stable cross-linked nonpolymeric tetramerichemoglobin suitable for use in mammals without causing renal injury and vasoconstriction is provided. A high temperature and short time (HTST) heatprocessing step is performed to remove undesired dimeric form of hemoglobin, 10 uncross-linked tetrameric hemoglobin, and plasma protein impurities effectively.Addition of N-acetyl cysteine after heat treatment and optionally before heat treatment maintains a low level of met-hemoglobin. The heat stable cross-linked tetramerichemoglobin can improve and prolong oxygenation in normal and hypoxic tissue. In another aspect, the product is used in the treatment of various types of cancer such as15 leukemia, colorectal cancer, lung cancer, breast cancer, liver cancer, nasopharyngealcarcinoma and esophageal cancer. Another application is heart preservation insituations where there is a lack of oxygen supply in vivo, such as in heart transplant or oxygen-deprived heart.(No Suitable Figure)