Production of human hemoglobin in transgenic swine: an approach to a blood substitute.

Many significant challenges have to be met before a clinically useful hemoglobin-based blood substitute can be developed. A major issue is the choice of a production system. Transgenic swine have several features that appear to be suited to the abundant production of human hemoglobin. Here we show that authentic human hemoglobin can be made in transgenic pigs and purified by simple ion-exchange chromatography. The purified hemoglobin can be modified for testing and use as a blood substitute.