Horseshoe Crab to Test for Toxins

Clotting enzyme in the horseshoe crab has many benefits An NUS breakthrough in genetic engineering has created a rare win-win situation that benefits both man and horseshoe crab. The fortuitous development earned Associate Professor Ho Bow (Department of Microbiology) and Professor Ding Jeak Ling (Department of Biological Sciences) a prize at the Asian Innovation Awards, handed out by the Far Eastern Economic Review.

The husband-and-wife team has achieved a bioengineering feat in successfully cloning the enzyme that clots the blood of the horseshoe crab, making it one of nature's most sensitive sensors for toxic contaminants. The ugly, hard-shelled living fossil survives in its natural habitat of some of the dirtiest waters in the world because of the anti-toxins in its blood.

Since the 1950s, the ability of the horseshoe crab's blood to clot when it comes into contact with bacteria has been tapped by pharmaceutical companies to test the purity of sterilised medical equipment and products. The revenue earned from this source of naturally harvested blood has been estimated at US$50 million.

Artificially-produced enzyme can help protect the endangered species In developing the technology to produce the enzyme in a controlled environment, the two researchers have found an alternative source of sensor that is more stable and chemically consistent than nature's endowment. The good news for the horseshoe crab, which has already become an endangered species in the world, is the conservation protection offered by the artificially-produced clone.

A patent for the discovery of the compound, called Factor C, has been issued in the United States. The technology for its production was licensed to the American biotech company BioWhittaker, which is keen to use it to develop sterility test and antibiotics. Prof Ding and Ho earlier won Singapore's National Technology Award for their contribution to genetic engineering research.