After a long day in surgery, it's BioTime. The company develops water-based solutions to prevent massive blood loss after traumatic injury, preserve organs for transplant, or replace blood during such procedures as cardiac bypass. BioTime's Hextend has received FDA approval to maintain blood volume during surgery; the company hopes to extend its use to trauma situations. The firm continues to develop PentaLyte, a short-lasting blood volume replacement, and HetaCool, intended to replace blood volume in cryosurgery and preserve donated organs. Abbott Laboratories is licensed to make and sell Hextend in the US and Canada.