Figure 1.

Light microscopic images of silk fibroin samples: (A) Raw silk fibers consist of two silk fibroin fibers covered and glued by a layer of sericin. (B) Silk fibroin fibers after standard degumming (30 min boiling in 0.02 M Na₂CO₃) and (C) microwave degumming. The scale bar corresponds to 20 µm. (D) Mean weight loss after degumming. The weight loss after degumming is expressed as the mean of four independent experiments ± standard error of the mean (SEM).