To characterize microbiomes and other ecological assemblages, ecologists routinely sequence and compare loci that differ among focal taxa. Counts of these sequences convey information regarding the occurrence and relative abundances of taxa, but provide no direct measure of their absolute abundances, due to the technical limitations of the sequencing process. The relative abundances in compositional data are inherently constrained and difficult to interpret. The incorporation of internal standards (ISDs; colloquially referred to as ‘spike‐ins’) into DNA pools can ameliorate the problems posed by relative abundance data and allow absolute abundances to be approximated. Unfortunately, many laboratory and sampling biases cause ISDs to underperform or fail. Here, we discuss how careful deployment of ISDs can avoid these complications and be an integral component of well‐designed studies seeking to characterize ecological assemblages via sequencing of DNA.

中文翻译：

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对绝对丰度的追求：基于 DNA 的社区生态学的内部标准的使用。

为了表征微生物组和其他生态组合，生态学家通常对焦点分类群中不同的位点进行排序和比较。这些序列的计数传达了有关分类群的出现和相对丰度的信息，但由于测序过程的技术限制，提供了它们绝对丰度的直接测量。成分数据中的相对丰度本质上受到限制且难以解释。将内部标准（ISD；通俗地称为“spike-ins”）纳入 DNA 库可以改善相对丰度数据带来的问题，并允许近似绝对丰度。不幸的是，许多实验室和抽样偏差导致 ISD 表现不佳或失败。这里，