Springtime in South Carolina. Sea turtles and horseshoe crabs favor the state’s 2,876 miles of sandy coastline to lay their eggs. Strict laws protect the turtles. But the crabs? Scientists harvest them to save human lives.
Helmet-shaped horseshoe crabs are animals with segmented outer skeletons and jointed legs. Long, spear-like tails help right the crabs if ocean waves tumble them. Despite the name, the creatures are actually closer to spiders and scorpions than crustaceans. Horseshoe crab eggs are a primary fat source for more than a dozen migrating bird species. But it’s the crabs’ bright blue blood that interests scientists.
The shocking hue comes from its high copper content. But color isn’t the most amazing feature of the fluid. Proverbs 16:4 says, “The Lord has made everything for its purpose.” In His infinite wisdom, God made horseshoe crab blood the only known natural source of a valuable toxin-detecting substance.
A crab-blood extract called limulus amebocyte lysate (LAL) helps scientists screen medical products. Simply put, LAL clots when it encounters certain types of bacterial toxins. Medicines, vaccines, and medical devices such as IV bags, needles, artificial joints, and sterile wipes must be totally free of toxins before human contact. LAL from crabs allows researchers to detect toxins and thereby save lives.
To obtain LAL, harvesters transport tens of thousands of horseshoe crabs to laboratories. Scientists insert a needle into each crab’s heart and draw blood. After the procedure, scientists return the animals to the sea.
The blood harvesting has drawn criticism from conservationists. That’s because up to 30% of the crabs don’t survive the process. Conservationists also argue that removing the crabs affects other species, especially birds that depend on crab eggs.
Charles River Laboratories runs a horseshoe crab-bleeding operation. Charles River tests 55% of the world’s injectables and medical devices. “If it touches your blood, it’s been tested by LAL,” says senior vice president Foster Jordan. “And, more than likely, it’s been tested by us.”
Harvesting crab blood is time-consuming and expensive. It’s no wonder pharma companies have long sought a man-made substitute for LAL. They found one: recombinant factor C—or rFC.
Today, China, Europe, and Japan accept rFC as an LAL replacement. However, U.S. officials have not approved rFC. They aren’t yet sure of its safety for use with humans. They say rFC needs more study, and the middle of the pandemic didn’t seem like the time to experiment.
Jay Bolden is a biologist at American pharmaceutical company Eli Lilly. He has worked with both LAL and rFC. An avid bird-watcher, Bolden hopes his company will switch completely to rFC. He usually agrees with unhurried approval of new medical technologies. “But for this particular issue, we have the science to back it up,” Bolden says. “We just wish it would happen a little faster.”
Why? The God who puts eternal value on human lives made the provision of horseshoe crab blood for use in medicine to help preserve life and health.
Pray: Give thanks for God’s design in nature, and pray for researchers working to find solutions to medical problems; for wisdom for those making laws about which new technologies are helpful and which are harmful.
