Glass needle-based chromosome microdissection (midi) is a standard approach developed in the 1980s and remains more frequently applied in testing than the comparable technique using laser-based platforms. As the amount of DNA extracted by this technique is minimal and often in the range of picograms, the isolated DNA must be further amplified prior to use; the isolated amplified product can be readily utilized in multiple molecular research and diagnostic investigation. DNA libraries created by midi are either chromosome- or chromosome-region-specific. However, a critical component to this process is the need for timely chromosome preparation via the air-drying method not to exceed a ~2-3 h before midi is performed. Failure of this time-sensitive step often results in the chromosomes drying out after dropping, and upon initiation of the midi technique, the dissected material can jump away while touching by the needle, and collection of a suitable sample is inhibited. Herein, we demonstrate with a simple adaptation of the standard procedure, midi can be performed on semi-archived material stored for longer periods at -20°C. Thus, the critical step to obtain well-spread chromosome preparations can be completed under established conditions, for example, in the primary laboratory, stored at -20°C, and sent directly to specialized reference laboratories offering midi. In our study, we were able to obtain high-quality DNA libraries, as verified by gel electrophoreses and reverse fluorescence in situ hybridization, via midi extracted chromosome spreads derived from human, fish, snake, lampbrush, and insect stored for up to 6 months. © 2019 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.

中文翻译：

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半存档材料上的染色体显微解剖。

基于玻璃针的染色体显微解剖（midi）是1980年代开发的一种标准方法，与使用基于激光的平台的同类技术相比，其在测试中的应用更为广泛。由于通过这种技术提取的DNA数量很少，而且通常在皮克范围内，因此分离的DNA必须在使用前进一步扩增。分离的扩增产物可以容易地用于多种分子研究和诊断研究中。由midi创建的DNA文库是特定于染色体或特定于染色体区域的。但是，此过程的关键组成部分是需要通过风干法及时准备染色体，以在进行Midi前不超过〜2-3 h。这个对时间敏感的步骤的失败通常会导致染色体掉落后变干，并且，在开始进行midi技术时，被解剖的材料会在被针接触时跳开，从而抑制了合适样品的收集。在这里，我们证明了通过对标准程序的简单修改，就可以在-20°C下长时间存储的半存档材料上执行midi。因此，获得广谱染色体制备物的关键步骤可以在既定条件下完成，例如在初级实验室中，储存在-20°C下，然后直接送到提供midi的专门参考实验室。在我们的研究中，我们能够通过从人类，鱼类，蛇，画笔和昆虫中存储长达6个月的Midi提取的染色体扩散，获得高质量的DNA文库（通过凝胶电泳和反向荧光原位杂交验证） 。©2019作者。