Wednesday, March 5, 2014

Blood Battles

A bacteria is sauntering around an organism, ready to attack and wreak havoc, but what's that? A chemical comes and traps the bacteria in this big sticky-like goo. Now what I described was not something in a sci-fi novel, but actually something that scientists do today and it comes from an unlikely source, the horseshoe crab Limulus polyphemus. This crab which if encountered by a human in a shoreline would be probably ignored, has special blood that makes it a supreme bacteria killer.

In an article from The Atlantic, it talks about the medicinal benefits of extracting the blood from the horseshoe crabs. How it works is that a particular chemical called coagulogen is contained in the amoebocytes of the crabs blood cells. This chemical can detect traces of bacteria and then trap it in something that scientist Fred Bang coined as a “gel”. How scientists use it is effectively in the same vein, they take the coagulogen chemical and put it in a solution containing bacteria. If it did not have bacteria then no gel substance would be formed and one would know the solution contained no bacteria. This test, which is called Limulus amebocyte lysate test, or LAL for short is actually used for detecting contaminated substances. The PBS documentary Nature actually said “Every drug certified by the FDA must be tested using LAL, as do surgical implants such as pacemakers and prosthetic devices.”

Yet, with anything in this world, there are drawbacks. Millions of horseshoe crabs must be used to get tons of their blood. The horseshoe crabs don’t die though, but the blood draining has long term effects. A research done and published in The Biological Bulletin points out that female horseshoe crabs that have been bled are lethargic and slow and less likely return to the shoreline where they were found. This is significant because females mate near the shoreline but now do not possess the vitality to make the trip and this reduces chances to mate.

Biomedical research is accelerating at a blistering pace, as shown by the miracle which is the blood of horseshoe crabs. While benefitting the human race, we must also understand the effects it has on the species we use, making this not just a biomedical issue, but an ecological one as well.

Posted by Jacob Geier (5-B)


  1. Great read Jacob. Being a Massachusetts native I have spent a lot of time on the beach. One of my favorite beaches is Duxbury. I love this beach because of the bay, and one of the best parts about the bay is the hundreds of horseshoe crabs. I can remember one time when I was a kid and my family went to the bay, only to discover a group of kids throwing rocks at all the horseshoe crabs. My mom freaked out on them and tried to explain how important these animals are, and ever since then I have had a solid appreciation for them.

    One thing I am curious about is why humans haven't synthetically produced this protein that the horseshoe crabs naturally produce. It seems if we could isolate the gene and insert it into another organism, like Yeast, we could mass produce it, similar to how we make insulin. It would save the lives and well-being of many of these animals.

    Posted By Tim Daly

  2. Interesting topic. The actual article you linked to was a good read. I was just wondering if all of the crabs actually do survive the bleeding or if it was possible that some of them actually did die?

    1. ^^this comment was posted by Taylor Schille. My fault for forgetting my name!

  3. Interesting read! In the article you talk about how they drain the blood from horseshoe crabs and then put them back in their natural habitat. This is very interesting to me. I recall from my youth being at the beach in Falmouth, MA, and watching trucks come and take away horseshoe crabs from the beaches for medicinal use. Unfortunately, its seems that they never brought them back, and instead sacrificed them to medicine. Perhaps they have changed their techniques to be more humane than they used to be!

  4. This is very interesting, I have never heard of this before. I wonder if any related species of crabs or if another invertebrate contains the same chemical, or if we could analyze the coagulogen's structure and synthesize it in a lab.
    Posted by Kristen Whitehead