Unlucky Horseshoe

The copper-rich 'blood' of the marine Horseshoe crab (actually, a relative of spiders and scorpions) has been of great utility to medicine as it rapidly clots in the presence of bacterial endotoxins. This reaction means that the blood can be used to assess the safety of materials designed for injection (such as vaccines) or infusion. Essentially, it can prove that they have not become contaminated by bacteria. There is, of course, a downside for the crab and welfare groups were keen to have a synthetic alternative (recombinant Factor C) manufactured by the Swiss company Lonza adopted  (https://www.theguardian.com/environment/2020/may/31/crab-blood-to-remain-big-pharmas-standard-as-industry-group-rejects-substitute). After initial positive noises, the rule-making US Pharmacopeia has reportedly decided (apparently following pressure from Charles River) that people using the synthetic product will have to routinely confirm their results using Horseshoe crab blood. This will increase the amount of testing (and expense) and removes the incentive to use Lonza's product. The crabs will continue for now to be 'little bleeders', upsetting the welfare organisations.