Leibniz Institute of Photonic Technology Jena - Member of the Research Alliance "Leibniz Health Technologies", Albert-Einstein-Str. 9, 07745, Jena, Germany.
Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.
Anal Bioanal Chem. 2021 Aug;413(20):5193-5200. doi: 10.1007/s00216-021-03488-0. Epub 2021 Jul 2.
Raman spectroscopy is an analytical method to identify medical samples of bacteria. Because Raman spectroscopy detects the biochemical properties of a cell, there are many factors that can influence and modify the Raman spectra of bacteria. One possible influence is a proper method for isolation of the bacteria. Medical samples in particular never occur in purified form, so a Raman-compatible isolation method is needed which does not affect the bacteria and thus the resulting spectra. In this study, we present a Raman-compatible method for isolation of bacteria from bronchoalveolar lavage (BAL) fluid using density gradient centrifugation. In addition to measuring the bacteria from a patient sample, the yield and the spectral influence of the isolation on the bacteria were investigated. Bacteria isolated from BAL fluid show additional peaks in comparison to pure culture bacteria, which can be attributed to components in the BAL sample. The isolation gradient itself has no effect on the spectra, and with a yield of 63% and 78%, the method is suitable for isolation of low concentrations of bacteria from a complex matrix. Graphical abstract.
拉曼光谱是一种用于鉴定细菌医学样本的分析方法。因为拉曼光谱检测的是细胞的生化特性，所以有许多因素会影响和改变细菌的拉曼光谱。一种可能的影响是细菌的适当分离方法。特别是医学样本从未以纯形式出现，因此需要一种与拉曼兼容的分离方法，该方法不会影响细菌及其产生的光谱。在这项研究中，我们提出了一种使用密度梯度离心从支气管肺泡灌洗液（BAL）中分离细菌的拉曼兼容方法。除了从患者样本中测量细菌外，还研究了分离对细菌的产率和光谱影响。与纯培养细菌相比，从 BAL 液中分离出的细菌显示出额外的峰，这可以归因于 BAL 样本中的成分。分离梯度本身对光谱没有影响，并且该方法的产率为 63%和 78%，适用于从复杂基质中分离低浓度的细菌。
