A method for reeling fluorescent silk cocoons without exposure to high temperatures and the educational practice

Abstract

An experiment using silkworm dry cocoons with an inserted GFP gene using genetic recombination technology is being developed for use in high school classes. However, when the cocoons are reeled by high temperature cocoon cooking, the fluorescent protein is denatured by the heat. It is still difficult for students to reel GFP cocoons in limited lesson time while preventing the denaturation. With this background, we aimed to develop a new reeling method that can be experimented in limited lesson time and does not require exposure to high temperatures. As a result, we discovered that the sodium bicarbonate overnight method allowed liquid to enter the cocoon and made it perfect for reeling. Using this method, we were able to reel in GFP cocoons without high temperature and confirm the fluorescence of the reeled silks. As an educational practice, the experiment, the reeling of GFP cocoons using the sodium bicarbonate overnight method was conducted with third-year high school students, and the success rate of the students was high. This method can be implemented even in limited lesson time, and was found to a teaching material that students could be interested in silk.