Abstract
Generally it has been believed that the aqueous extracts of pure silk do not show the polarographic-protein-wave.
The authors, however, have observed the small polarographic-protein-wave with colloidalsolution of sericine which is prepared from cocoon shells of Bombyx mori and a distinctcystine wave with sericine hydrolysates. Fibroin hydrolysates also show a distinct cystine wave.
It was found that cocoon fibres contained cystine and sericine B contained a great dealof cystine comparing with sericine A.
The reality of these cystines are proved polarographically by means of addition of purecystine and treatment of hydrogen peroxide, and cystine contents in these hydrolysates couldbe determined with polarographic method.
