Canadian Manufacturing

Clean needles depend on the blue blood of horseshoe crabs

There is a synthetic alternative to the horseshoe crab blood, but it hasn't been widely accepted in the U.S.

August 20, 2021  by Associated Press

It’s one of the stranger, lesser-known aspects of U.S. health care — the striking, milky-blue blood of horseshoe crabs is a critical component of tests to ensure injectable medications such as coronavirus vaccines aren’t contaminated.

To obtain it, harvesters bring many thousands of the creatures to laboratories to be bled each year, and then return them to the sea — a practice that has drawn criticism from conservationists because some don’t survive the process.

The blood, which is blue due to its copper content, is coveted for proteins used to create the LAL test, a process used to screen medical products for bacteria. Synthetic alternatives aren’t widely accepted by the health care industry and haven’t been approved federally, leaving the crabs as the only domestic source of this key ingredient.

Many of these crabs are harvested along the coast of South Carolina, where Gov. Henry McMaster promoted the niche industry as key to the development of a domestic medical supply chain, while also noting that environmental concerns should be explored.

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“We don’t want to have to depend on foreign countries for a lot of reasons, including national security, so it’s good to see this company thriving in the United States,” McMaster told The Associated Press this month during a visit to Charles River Laboratories at its Charleston facilities, to which AP was granted rare access. “We want to do everything we can to onshore all of these critical operations.”

Horseshoe crabs — aquatic arthropods shaped like helmets with long tails — are more akin to scorpions than crabs, and older than dinosaurs. They’ve been scurrying along the brackish floors of coastal waters for hundreds of millions of years. Their eggs are considered a primary fat source for more than a dozen species of migratory shore birds, according to South Carolina’s Department of Natural Resources.

Their value to avoiding infection emerged after scientists researching their immune response injected bacteria into horseshoe crabs in the 1950s. They ultimately developed the LAL test, and the technique has been used since the 1970s to keep medical materials and supplies free of bacteria.

Their biomedical use has been on the rise, with 464,482 crabs brought to biomedical facilities in 2018, according to the Atlantic States Marine Fisheries Commission.

There is a synthetic alternative to the horseshoe crab blood, but it hasn’t been widely accepted in the U.S., and meanwhile, Charles River’s international competitors are making synthetics and also pressing for U.S. Food and Drug Administration approval, which Jordan said could hamper domestic efforts like his own.