Certain spider’s can produce silk that is extremely elastic and strong; many molecular biologists want to explore it’s properties for that reason. But unfortunately, spiders can be difficult to deal with in large quantities so other methods of obtaining the precious silk must be found. A current method? Goat milk.
When raising spiders, the territorial nature of the arthropods comes to light (which often involves attack and cannibalism). If you are to study spider silk, however, you need large quantities and spider silk can cost several times more than its weight in gold. This is where Professor Randy Lewis (currently at Utah State University) started his research.
Spider silk is formed from two main proteins. These proteins, Professor Lewis and other researchers realized, could be individually produced within goat milk and combined later in large amounts. And they do this through an amazing act of genetic engineering. Several goats are given the gene to produce the proper proteins, and in some of these goats the genes are activated. Currently, there are over 30 of these goats.
The process of creating the silk involves a few steps. First, the goats are separated into the two groups dependent on which of the two proteins they produce. After milking, the milk is frozen to remove most of the cream and a filter is used to remove the rest of the cream. Now the two proteins have been extracted and dried, but different methods need to be used to produce different kinds of spider silk.
There are six types of silk that spiders usually produce, each made using a different process that gives different properties. Professor Lewis’ team has managed to create a thicker silk thread by, quite literally, pulling the two mixed proteins through the end of a needle. A process which Professor Lewis says “they pull it out like floss, not push it out like toothpaste.”
Once the silk is produced, the possibilities for its use seem endless. Spider silk has potential uses in medicine (as artificial tendons and ultra-thin sutures), engineering (as bulletproof vests and lightweight, but strong cables), and even has potential for strange properties in textiles. In fact, two textiles have been produced already: a cape and a tapestry. I leave you with a video addressing the 2.6 pound tapestry made of silk from over 1-million spiders.