With two pairs of fine-tipped tweezers and the hands of a surgeon, Cheryl Hayashi began dissecting the body of a silver garden spider under her microscope.
In just a few minutes, she found what she was seeking: hundreds of silk glands, the organs spiders use to make their webs. Some looked like mashed potatoes, others like green worms or air-filled rubber gloves. Each lets the spider produce a different type of silk.
Some silk types can be stretchy, others stiff. Some dissolve in water, others repel it.
“They make so many kinds of silk!” Hayashi said. “That’s just what boggles my mind.”
Hayashi has collected spider silk glands of about 50 species, just a small dent in the more than 48,000 spider species known worldwide. Her lab at the American Museum of Natural History is uncovering the genes behind each type of silk to create a sort of “silk library.” It’s part of an effort to learn how spiders make so many kinds of silk and what allows each kind to behave differently.
The library could become an important storehouse of information for designing new pesticides and better materials for bullet-proof vests, space gear, biodegradable fishing lines and even fashionable dresses.
Hayashi has been at this for 20 years, but improved technology only recently let scientists analyze the DNA of silk faster and produce artificial spider silk in bulk.