Leef J L, Strome C P, Beaudoin R L
Bull World Health Organ. 1979;57 Suppl 1(Suppl):87-91.
Large numbers of biologically active sporozoites are needed as a source of potential antigen in the development of a malaria vaccine and the most practical method of accumulating sufficient numbers of these forms would be to freeze and store them at low temperature. The purpose of this work was to determine the feasibility of preserving the infectivity of frozen and thawed sporozoites. The results indicate that sporozoites of Plasmodium berghei exhibit a typical response to freezing over a wide range of cooling rates; the distribution around the optimum was a normal one and both the magnitude and position of the peak of their infectivity depended upon the preservative used. The optimum cooling rate with preservatives of high relative molecular mass was between 20 degrees C and 60 degrees C per min, but varied with the preservative used. A new apparatus was designed and built to yield reproducible controlled cooling rates over the range studied. A comparison of various commonly used preservatives showed mouse serum alone to be effective, but the combination of serum and hydroxyethyl starch proved to be the best cryopreservative of those examined.
在疟疾疫苗的研发中，需要大量具有生物活性的子孢子作为潜在抗原的来源，而积累足够数量这些形态的最实用方法是将它们冷冻并低温保存。这项工作的目的是确定保存冷冻和解冻子孢子感染力的可行性。结果表明，伯氏疟原虫的子孢子在广泛的冷却速率范围内对冷冻表现出典型反应；在最佳值周围的分布呈正态分布，其感染力峰值的大小和位置都取决于所用的防腐剂。使用高分子量防腐剂时的最佳冷却速率在每分钟20摄氏度至60摄氏度之间，但随所用防腐剂而变化。设计并制造了一种新装置，以在所研究的范围内产生可重复的受控冷却速率。对各种常用防腐剂的比较表明，仅小鼠血清有效，但血清和羟乙基淀粉的组合被证明是所检测的最佳冷冻保护剂。
