The bioactivity tests showed that the induce resistance of oligochitosan was close relation with its degree of polymerization (DP) and its degree of deacetylation (DDA), the oligochitosan with low DP and high DDA has high induce resistance. In this paper, we used HPLC method and TOF-MS method detecting the DP and DDA of oligochitosan.

Objective To investigate the effects of oligochitosan on the humoral and cellular immunity in mice.Methods Divided the mice into four groups,test groups were given ip oligochitosan at doses of 60,120,240 mg?kg~(-1) for 14 days and the control group was given(0.9%) NS. The number of haemolytic empty spots,the level of serum hemolysin,the transform rate of T lymphocytes induced by ConA,delayed hypersensitivity were measured.Results Compared with the control group,indices including the number of haemolytic empty spots,the level of serum hemolysin,the transform rate of T lymphocytes induced by ConA,spleen ratio,ears swelling degree increased obviously in the dose of 120mg?kg~(-1) after two weeks of treatment.Conclusion Proper dose of oligochitosan can enhance the specific humoral and cellular immunity in mice.