日本血吸虫童虫液氮冷冻保藏期的研究

Studies on the Storage Life of Schistosoma japonicum Schistosomules Cryopreservated in Liquid Nitrogen

日本血吸虫童虫经２４ｈ到２年冻藏后，其活力和感染率与冻藏时间长短不相关，与冻存培养液的ｐＨ相关，最佳ｐＨ为７。冻藏５０ｄ传至Ｆ４，冻藏２年传至Ｆ１。童虫及其子代在终宿主小鼠和中间宿主钉螺体内的移行、生长、发育、繁殖、传代、性别比率及对终宿主的致病力，同相应对照组无明显差异，由此证明日本血吸虫童虫可用液氮冻藏长期保种。

The experiments indicated that all of seven different periods(from 24hours to 2 years)have not influenced upon their viability and infection rate,but a corre-lation with the pH value of culture media existed.In comparing the characters,such asgrowth,development,reproduction in the final host(mice)and intermediate host(on-comelanial snails),sex ratio of adults and the pathogenicity for final host of the uncry-opreservated schistosomules,there were no obvious differences between them. Thus,it-has proved that S. japonicum schistosomules could be cryopreservated in liquid nitrogenfor a long time.