B. mori silk fibers are reported to have sericin content ranging from 20 to 30 % and mild alkali at 90 °C and degumming without ethylenedi- amine or other chelating agents are normally adequate for B. mori silk [22]. It has also been reported that the sericin content in cocoons progressively decreases from the outside layers to the inside layers similar to that ob- served for the A. atlas cocoons in this research [23]. The sericin content in the B. mori cocoons varied from about 30 % in the outer layer to about 20 % in the inner most layer [23]. Although sericin needs to be removed from silk fibers to make the fibers lustrous, sericin proteins are found to have unique properties and used for applications in various areas. Sericin resists oxidation, has antibacterial and anti-UV resistant properties [22, 24].Silk sericin has been used for medical, pharmaceutical and cosmetic industries [24, 25]. Morphology of the Layers in the A. atlas Cocoons