Scientists may be close to an elusive goal of creating artificial blood, a breakthrough that could ease shortages and save countless lives.

Biopure Corp. in Cambridge, Mass., has produced artificial hemoglobin from the red blood cells of cows. It has been cleared for use in the Republic of South Africa and is awaiting Food and Drug Administration review of its phase III clinical trials in the United States. U.S. Northfield Laboratories, in Oakden, South Australia, has developed Polyheme, a polymerized human hemoglobin product, and Hemosol Inc. in Toronto has developed Hemolink, a partially polymerized human hemoglobin that also is under FDA review.

In the United States, where the safety of the blood supply has constantly improved over the past 20 years, artificial blood would most likely be used in emergencies, according to Squires. It would eliminate the need to match blood types before providing transfusions to trauma victims. When donor supplies get tight, artificial blood could help alleviate the shortage.