The localization of viral nucleic acids in the cell is essential for understanding the infectious cycle. One of the strategies developed for this purpose is the use of nucleotide analogs such as bromodeoxyuridine (BrdU, analog to thymine) or bromouridine (BrU, analog of uridine), which are incorporated into the nucleic acids during replication or transcription. In adenovirus infections, BrdU has been used to localize newly synthesized viral genomes in the nucleus, where it is key to distinguish between host and viral DNA. Here, we describe our experience with methodological variations of BrdU labeling to localize adenovirus genomes in fluorescence and electron microscopy. We illustrate the need to define conditions in which most of the newly synthesized DNA corresponds to the virus and not the host, and the amount of BrdU provided is enough to incorporate to the new DNA molecules without hampering the cell metabolism. We hope that our discussion of problems encountered and solutions implemented will help other researches interested in viral genome localization in infected cells.

中文翻译：

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溴脱氧尿苷标记在荧光和电子显微镜下确定病毒 DNA 定位：以腺病毒为例

病毒核酸在细胞中的定位对于理解感染周期至关重要。为此目的开发的策略之一是使用核苷酸类似物，例如溴脱氧尿苷（BrdU，胸腺嘧啶类似物）或溴尿苷（BrU，尿苷类似物），它们在复制或转录期间掺入核酸中。在腺病毒感染中，BrdU 已被用于在细胞核中定位新合成的病毒基因组，这是区分宿主和病毒 DNA 的关键。在这里，我们描述了我们在荧光和电子显微镜下定位腺病毒基因组的 BrdU 标记方法变化的经验。我们说明需要定义大多数新合成的 DNA 对应于病毒而不是宿主的条件，并且所提供的 BrdU 的量足以整合到新的 DNA 分子中，而不会妨碍细胞的新陈代谢。我们希望我们对遇到的问题和实施的解决方案的讨论将有助于其他对感染细胞中病毒基因组定位感兴趣的研究。