Saturday science subject: Converting blood
A team of scientists led by the University of Copehnagen in Denmark has come up
with a way to convert blood from groups A, B, and AB into group O rhesus negative blood, as BBC News reports. O- blood can be transfused into a patient with any blood type, whereas compatibility between A, B, and AB groups is more selective. The scientists successfully converted blood using two types of bacteria:
The blood cells of people with group A and B blood contain one of two different sugar molecules, which act as "antigens", triggering an immune system response. People with AB blood have both types of molecule, while those with group O blood have neither. . . . The new technique works by using bacterial enzymes to cut sugar molecules from the surface of red blood cells. After a search of 2,500 fungi and bacteria the researchers discovered two bacteria - Elizabethkingia meningosepticum and Bacterioides fragilis - which contained potentially useful enzymes. They found that enzymes from both bacteria were able to remove both A and B antigens from red blood cells.
However, only rhesus negative blood from groups A, B, and AB can be converted. The new process cannot convert A+, B+, or AB+ blood types into O-. Nonetheless, Geoff Daniels, of the Bristol Institute for Transfusion Sciences in the UK, and Stephen Withers, of the University of British Columbia in Canada, tell BBC News the method "may enable manufacture of universal red cells, which would substantially reduce pressure on the blood supply." Patient trials will be needed before the conversion process can be used in hospitals, though.