Biomedical
Industry
photo:BioWhittaker
The biomedical
industry is very interested in the horseshoe crab, too. The horseshoe crab
is the most researched marine invertebrate in the world. Researchers have
investigated its eyes, its shell, and its blood.
In 1967 the
study of horseshoe crab eyes helped Dr. Keifer Hartline win the Nobel Prize
for his research on the mechanics of human vision. Several other Nobel
awards have been based on horseshoe crab eye research. Two of the eyes
of the horseshoe crab are compound. They are very similar to the human
eye, but parts are bigger so it makes them easier to use in research.
The shell
of the horseshoe crab has been important to scientists, too. There is a
chemical in the horseshoe crab's shell called chitin. Contact lenses, skin
creams, and hair sprays can be made from this substance. It is used in
dye in the textile industry, in waterproofing of paper, and in chicken
feed in combination with whey. It's also used for removing lead from drinking
water and other harmful chemicals from wastewater. Chitin can be put in
foods to get rid of the fat. It clings to the fat while you eat the food,
and the fat is not digested. Chitin is also used in sheets for burn victims
and to sew up wounds. The stitches dissolve slowly and less people are
allergic to them. The dressings actually promote the healing.
Although there
are many uses for chitin, the blood of a horseshoe crab is maybe even more
important. A test called the Limulus amebocyte lysate (LAL) is used to
test for bacterial toxins and saves millions of lives every year. LAL
is made from the blood cells found in the horseshoe crabs' unique copper-based
blood. The blood of a horseshoe crab is blue because the blood has
copper inside. The blood can fight deadly diseases. The blood is collected
by flexing the joint between the head and the abdomen, making way for a
hypodermic needle. Then the needle is inserted in the crab’s cardiac chamber
and the blood drips into a collecting bottle.
photo permission: BioWhittaker
The crabs are gathered in the spring
and summer when the water is warmer and they come to shallow water to mate.
The crabs are taken to labs where about one-third of their blood is drawn.
Then they are returned to the water. Within three days the crabs will regenerate
their blood. The LAL is used to test the purity of vaccines, injectable
drugs, intravenous solutions, syringes, prosthetic devices (like hip replacements
and artificial hearts) and any medical equipment that comes in contact
with our blood. BioWhittaker is a company that makes LAL. It sent us a
presentation about how it does this process. Click
here to see that presentation. Only six or seven companies are licensed
to produce LAL. Limuli Laboratories in N.J. is the only Delaware Bay collector.
It bleeds for Endosafe.
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horseshoe crabs