Kupke D W, Beams J W
Proc Natl Acad Sci U S A. 1977 May;74(5):1993-6. doi: 10.1073/pnas.74.5.1993.
The solid-like behavior of turnip yellow mosaic virus solutions following the extrusion of viral RNA in alkali was observed with a torsion-fiber balance developed for the purpose. This method provided a direct measurement of the yield stresses required to break or liquefy these solutions. The yield stresses were found to increase and to be less time dependent with increasing concentrations of the virus and they were maximal at room temperatures. If the virus had been damaged, as by freeze-thaw, little or no solid-like behavior could be demonstrated. Purified viral capsids, with or without added RNA, were also inactive. The values for the yield stresses were of the same order as the value reported previously with the use of a magnetic suspension viscometer; hence, the apparent coherency appears unrelated to the magnetic fields generated by the latter instrument. These solutions behaved as typical liquids after the required stress was applied [about 0.005 to 0.17 dyne cm-2 (0.05 to 1.7 micronN cm-2)], these forces being smaller than those usually conferred by ordinary handling.
使用为此目的开发的扭力纤维天平，观察到芜菁黄花叶病毒溶液在碱性条件下挤出病毒RNA后呈现出类似固体的行为。该方法直接测量了破坏或液化这些溶液所需的屈服应力。发现屈服应力随着病毒浓度的增加而增加，且对时间的依赖性较小，并且在室温下达到最大值。如果病毒受到如冻融等损伤，则几乎或无法表现出类似固体的行为。纯化的病毒衣壳，无论是否添加RNA，也均无活性。屈服应力的值与先前使用磁悬浮粘度计报告的值处于同一数量级；因此，表观相干性似乎与后一种仪器产生的磁场无关。在施加所需应力[约0.005至0.17达因/平方厘米（0.05至1.7微牛顿/平方厘米）]后，这些溶液表现为典型的液体，这些力小于通常由普通操作施加的力。
