Kraig Biocraft Laboratories Inc., Lansing, Mich., has created "Big Red," a new recombinant spider silk variety that it reports is stronger than previously developed varieties.

Two varieties of the fiber, whose color has a slight red cast, are being spun by transgenic silkworms that have two different spider silk genetic sequences. It is a follow-up to the company's hybrid Monster Silk™, which is on track to be in commercial production in the first half of 2013, reports CEO Kim Thompson.

"This new type of fiber was designed to be a combination of spider silk proteins, silkworm silk proteins and protein from an unrelated species," Thompson said. "What significantly differentiates this material from our Monster Silk™ is the unique spider silk genetic sequence that we used, which we designed to increase strength-to-weight ratios. Another important difference is the incorporation of a unique protein, which gives the new fiber its designation as 'red.'"

Big Red is stronger than Monster Silk but not as elastic. Thompson sees its applications particularly in technical textiles that require added strength but in which elasticity would not be desirable.

March/April 2013