Materials
Carica papaya fruits were harvested from
70-100 days maturation of papaya trees
planted in Chiang Mai, Thailand. Standard
purified papain (95% purity) and chymopapain
(90% purity) were purchased from Sigma
(USA). Polyacrylamide, bis-acrylamide,
ammonium persulfate, and tetramethylenediamide
(TEMED) were obtained from
Sigma-Aldrich (USA). Ethanol, iso-propanol,
methanol and ammonium sulfate were
supplied by Fluka (USA)