What is the function of horseshoe crab blood?

Horseshoe crab itself is a kind of Chinese herbal medicine. From the perspective of traditional Chinese medicine, it is warm in nature and salty in taste. After ingestion, it can clear away heat and fire, calm the liver and suppress yang, promote blood circulation and remove blood stasis. It has a certain improvement effect on sore throat caused by hyperactivity of liver yang, mouth sores caused by factors that easily cause fire, and limb pain caused by blood stasis. From a pharmacological point of view, it is rich in sodium ions and protein. After intake into the body, it can increase the strength of bones and provide rich energy for basal metabolism.

Horseshoe crab has high efficacy and function, and its whole body is a treasure. Its meat, shell and tail can all be used as medicine. The growth cycle of Chinese horseshoe crab is relatively long, and it takes nearly 13 years for it to reproduce. But horseshoe crab resources have now been drastically reduced. Due to land reclamation, tidal flat development and other reasons (because horseshoe crabs are very picky about where they grow), horseshoe crabs have lost the shallow sea beaches on which they depend for survival.

Another selfless contribution of horseshoe crabs to humans is their blood. In 1956, it was discovered that after horseshoe crabs were introduced with Gram-positive and Gram-negative bacteria, they quickly died from blood coagulation. After 8 years of persistent exploration, it turned out that the lethal molecule "toxin accumulation" produced by the cytoplasm of Gram-positive and Gram-negative bacteria activated an enzyme in the cells of horseshoe crab hemomorphs.

This causes blood protein to change from a sol to a gel and coagulate. The experiment of using horseshoe crab blood to detect the presence of Gram-positive and Gram-negative bacteria is called the "horse crab test" in the medical field. The sensitivity of the horseshoe crab test is very high. It can detect toxin accumulation of 1 mg/ml or even 1 picogram/ml, and the detection speed is faster, only taking 15 minutes. Today, the dried slice "horseshoe crab reagent" made from horseshoe crab blood has been quickly used in the diagnosis of diseases such as meningitis, cholera, plague, whooping cough, etc. caused by Gram-positive and Gram-negative bacteria. In addition, significant progress has been made in drug testing, food hygiene, and environmental monitoring.

However, it takes horseshoe crabs 8 long years to grow into adults. Killing horseshoe crabs and drawing blood is not only useless but will also lead to the depletion of horseshoe crab resources. Each female horseshoe crab can lay 80,000 eggs and extract 50 ml of blood. Their blood turns blue when it comes into contact with oxygen. After purification, refrigeration and drying, it is in powder form. Horseshoe crabs are artificially raised in the South China Sea, and products made from horseshoe crab reagents made from live blood tests are also on the market.