National University of Singapore
Because horseshoe crab blood immediately clots when it comes into contact with bacteria, the blood of this unique animal has been used for decades by pharmaceutical companies for testing the purity of sterilized medical equipment and human injectable products. Although this quality assurance method is effective, it is costly, timeconsuming, and suffers batch-tobatch variations in sensitivity, and could possibly kill the horseshoe crab, which is now considered an endangered species in various parts of the world. Now, however, a genetic engineering breakthrough at the National University of Singapore has cloned the enzyme that clots the blood of the horseshoe crab.
A novel generation of cloned horseshoe crab recombinant Factor C for detection and removal of endotoxin was discovered in 1998 by professor Ding Jeak Ling of the department of biological sciences, and associate professor Ho Bow of the department of microbiology.
The cloned “Factor C” enzyme reacts
to bacteria and endotoxins at extremely
low levels, and is more stable and
chemically consistent than the naturally
occurring form. This technology also
enables Factor C to be produced without
having to bleed horseshoe crabs, which
will help conserve this dwindling species.
The Factor C recombinant technology
has been licensed by the National
University of Singapore to several
companies, including BioDtech and
Lonza, a global life sciences company
based in Switzerland. Lonza is using the
cloned enzyme in both their Pyrogene™
and PyroSense™ systems with Pyrogene
being an endotoxin detection kit whilst
PyroSense is an online endotoxin