Natural fiber exoskeletons of insects and arthropods. In shells and exoskeletons, the chitin fibers contribute to their hierarchical structure. In nature, pure chitin (100% acetylation) does not exist. It instead exists as a copolymer with chitin's deacetylated derivative, chitosan. When the acetylized composition of the copolymer is over 50% acetylated it is chitin. This copolymer of chitin and chitosan is a random or block copolymer. Chitosan is a deacetylated derivative of chitin. When the acetylized composition of the copolymer is below 50% it is chitosan. Chitosan is a semicrystalline “polymer of β-(1-4)-2-amino-2-deoxy-D-glucose”. One difference between chitin and chitosan is that chitosan is
Insect cell culture Insect cell culture The use of insect cell lines as production hosts is an emerging technology for the production of bio pharmaceuticals. There are currently more than 100 insect cell lines available for recombinant protein production with lines derived from "Bombyx mori", "Mamestra brassicae", "Spodoptera frugiperda", "Trichoplusia ni", and "Drosophila melanogaster" being of particular interest. Insects cell lines are commonly used in place of prokaryotic ones because post-translational modifications of proteins are possible in insect cells whereas this mechanism is not present in prokaryotic systems. The Sf9 cell line is one of the most commonly used lines in insect cell