几种冷冻保存伊氏锥虫方法的比较试验研究

COMPARATIVE STUDY ON DIFFERENT METHODS OFPRESEVING TRYPANOSOMA EVANSI BY LIQUIDNITROGEN CRYOFREEZING

本文用液氮冷冻法比较了不同保护剂和不同冻存途径对伊氏锥虫云南株进行保存后，虫株在存活率、活力、感染力、致病力和药敏性方面的变化。我们发现在以二甲基亚砜为主要保存剂时，二甲基亚砜浓度低对保存效果不利，而浓度为５％时，保存７１２天后，虫体成活率仍达９６％；当以甘油为保存剂时，若其浓度低虫体成活率低，当浓度为２０％时，保存３６５天后虫体存活率有９１．４％。在不同冻存途径试验中发现，先在液氮气相中距液氮面４ｃｍ以上处放置１ｈ，再降到距液氮面４ｃｍ处放置１ｈ，然后进入液氮效果最好。用此种保存方法和冻存途径后，虫体活力强，其感染力、致病性和药敏性都没有发生明显变化。

The effect of different preservers and different preserving pathways on the liv ing rate, activity, infectivity. pathogenicity and drug sensitivity of Trypanosoma evansi byliquid nitrogen cryofreezing is studied. High living rate can not be found when the concen tration of dimethyl sulfoxide and glycerol is low. But with 5% dimethyl sulfoxide the livingrate of Trypanosoma evansi is 96% after preserving for 712 days; and with 20% glycerol theliving rate is 91.4% after 365 days. In the study of different freezing pathways it is showedthat high living rate can be obtained by first placing the preserving system in gas nitrogenat a distance of more than,4 cm away from liquid nitrogen for one hour, then dipping it intoliquid nitrogen after placing it at a distance of 4 cm away from liquid nitrogen for anotherone hour. In the experiment we have not found any distinet change about the activity. infec tivity, pathogenicity and drug sensitivity of Trypanosoma ovansi.