Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, USA.
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA.
Bioessays. 2022 Feb;44(2):e2100070. doi: 10.1002/bies.202100070. Epub 2022 Jan 6.
A recent article argued that signals from conventional Raman spectroscopy of organic materials are overwhelmed by edge filter and fluorescence artefacts. The article targeted a subset of Raman spectroscopic investigations of fossil and modern organisms and has implications for the utility of conventional Raman spectroscopy in comparative tissue analytics. The inferences were based on circular reasoning centered around the unconventional analysis of spectra from just two samples, one modern, and one fossil. We validated the disputed signals with in situ Fourier-Transform Infrared (FT-IR) Spectroscopy and through replication with different lasers, filters, and operators in independent laboratories. Our Raman system employs a holographic notch filter which is not affected by edge filter or other artefacts. Multiple lines of evidence confirm that conventional Raman spectra of fossils contain biologically and geologically meaningful information. Statistical analyses of large Raman and FT-IR spectral data sets reveal patterns in fossil composition and yield valuable insights into the history of life.
最近的一篇文章认为，有机材料的常规拉曼光谱信号被边缘滤光片和荧光伪影所淹没。这篇文章针对的是化石和现代生物的拉曼光谱研究的一个子集，对常规拉曼光谱在比较组织分析中的应用有影响。这些推论是基于对仅来自两个样本的光谱的非传统分析，一个是现代样本，一个是化石样本，得出的循环推理。我们使用原位傅里叶变换红外（FT-IR）光谱学对有争议的信号进行了验证，并通过在不同的实验室中使用不同的激光器、滤光片和操作人员进行了复制。我们的拉曼系统采用全息陷波滤光片，不受边缘滤光片或其他伪影的影响。多种证据证实，化石的常规拉曼光谱包含具有生物学和地质学意义的信息。对大型拉曼和 FT-IR 光谱数据集的统计分析揭示了化石成分中的模式，并为生命历史提供了有价值的见解。
