Thanks your advise. I prepared the colloidal chitin according the method described at https://www.researchgate.net/post/How_do_I_prepare_water_soluble_colloidal_chitin, except the procedure autoclaving. finally, I failed to measure the chitinase activity using this colloidal chitin( the glucouse were detected using lamimarin). dose it might caused by the lacking of autoclaving?
The substrate used to assy,purify and characterize chitinolytic enzymes from Trichoderm include p-nitrophenyl chitoolgomers,differently purified chitin or fungal cell wall.I thank you can purified chitin from excuvium of insects or cray fish.Trichoderma&Gliocladium edited by Christian P.Kubick and Gary E.Harman maybe useful for you .good luck