🤪 Fun & Weirdpublished 2w ago
Horseshoe Crabs Have Sky-Blue Blood That Protects Modern Medicine
Horseshoe crabs do not have red blood. Instead of iron-based hemoglobin, their oxygen travels via copper-based hemocyanin, giving their blood an otherworldly milky-blue color. Even stranger, their blood cells clot almost instantaneously in the presence of bacterial endotoxins. For decades, medical labs have harvested this blue fluid to create tests that ensure every human vaccine, IV drip, and surgical implant is completely free of bacterial contamination.
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