Sericin Extraction from Silkworm Cocoons

The silkworm cocoons (J108 strain) were obtained from Queen Sirikit Sericulture Center (Khon Kaen, Thailand) in January 2020. Cocoons were aged 42 days at collection. The silkworm cocoon was cut into small square pieces of 1 × 1 cm. Twenty-four grams of cocoon materials were added to 700 mL of purified water and autoclaved (Tomy-SX-700, Tokyo, Japan) at 120 °C, 2.5 bar for 60 min. After filtration through Whatman No. 1, the filtrate was freeze-dried at −85 °C, 0.595 bar (Labconco, Kansas, MO, USA) to obtain the sericin extract [18 (link)]. The sericin extract was stored at 4 °C before use. The protein content was determined by Bradford assay and molecular weight profiles were determined by polyacrylamide gel electrophoresis (SDS-PAGE) [18 (link)].