Scientists in Singapore are using gene technology to develop a rainbow range of flurescent fish that could eventually be used to detect water-borne pollution. Zhiyuan Gong, a biology professor at the National University of Singapore, has produced a fluorescent green-and-red zebra fish, and his laboratory has the technology to create a kaleidoscopic palette to five colours in genetically modified fish, he told the Pacfic Rim Biotechnology Conference in Vancouver.