PPL to put human genes into cows

PPL Therapeutics, the biotech company that produced Dolly, the world's first cloned sheep, and Polly, the first sheep to contain a human gene, yesterday announced its next major goal - a blood transfusion product. Dr Ron James, PPL's managing director, aims to replace a cow gene with a specific human gene.

The long-term aim is to replace the bovine serum albumin gene in cows with the human serum albumin gene. Doing that would enable PPL to produce, in cows' milk, large quantities of plasma extender protein. The protein is essential in treating victims who have suffered massive blood loss.

Administering the plasma, a part of whole blood, substitutes for a traditional blood transfusion without wasting time matching blood types. At present, around 600 tonnes of plasma extender is administered every year in the UK - a market worth pounds 2bn. Manufacturing such large quantities of the protein is difficult and costly. But using cows' milk would speed up the process. The first step is proving that human genes can be transferred into cow cells.