A US biotech firm is joining forces with the researchers who cloned Dolly the sheep to develop a new technology to produce disease-free organs for use in human transplants. Kimeragan, based in Newton, Pennsylvania, is hoping to combine its new approach to gene therapy, called chimeraplasty, with the cloning technology developed by Roslin scientists to create herds of disease free animals. 'The hope is to create herds of sheep that are free from scrapie, the ovine equivalent of mad cow disease, whose organs are similar enough to human organs to be used for human transplantation,' said Kimeragen chief executive Gerald Messerschmidt on Wednesday 21 October.