Stein P, Gann M K, Baxter W L
Microbios. 1976;15(60):135-43.
Influenza C was propagated by serial undiluted passage; conditions known to produce non-infectious (von Magnus) particles with influenza A and B. Following each passage infectious material was assayed for infectivity and haemagglutinating activity and the values related by calculating the log difference between infectivity and haemagglutinating titre (I:A ratio). Infectious material from each pass was examined for ultrastruct aberrations by negative strain electron microscopy. Influenza C exhibited a significantly smaller decrease in I:A ratio than exhibiyed by similarly propagated influenza A and B. Ultrastructural examination of the serially passed influenza C revealed no production of morphologically aberrant forms, whereas serially passed influenza B produced a strikingly altered morphology.
丙型流感病毒通过连续未稀释传代进行增殖；已知这些条件会产生甲型和乙型流感的非感染性（冯·马格努斯）颗粒。每次传代后，对感染性物质进行感染性和血凝活性检测，并通过计算感染性和血凝滴度之间的对数差（I:A比值）来关联这些值。通过负染电子显微镜检查每次传代的感染性物质的超微结构异常。丙型流感病毒的I:A比值下降幅度明显小于同样传代的甲型和乙型流感病毒。对连续传代的丙型流感病毒进行超微结构检查发现未产生形态异常的形式，而连续传代的乙型流感病毒则产生了明显改变的形态。
