Development of Teaching Materials for a High School Chemistry Lab Experiment Using Silk Cocoon Fibroin

—For Protein Detection Reaction and Staining Experiment—

Abstract

In a unit of high school chemistry, fibroin is treated as an example of a natural polymer compound. However, practical examples of chemistry experiments related to the chemical properties of silk fibroin have not been reported. In this research, we devised a chemistry experiment to be completed in a class assumed to be 50 minutes long. It was recognized that the fibroin solution obtained by dissolving raw cocoons could be applied to experimental teaching materials as a standard protein in protein detection experiments. In the experiment, dyeing, which is a method of discriminating the fibers of the polymer compound, the insolubilized regenerated fibroin film showed a coloration peculiar to the animal fiber. Fibroin chemically treated as recycled fiber has properties of natural fiber, which is suitable as a teaching material for experiments compared with chemically synthesized fiber. Experiments using fibroin at dissolution, dialysis and membrane production suggested that it is suitable for students’ basic chemical experiments without requiring special laboratory instruments, toxicant substances, or effluent treatment work.