de Bruijn Douwe S, Ter Braak Paul M, Van de Waal Dedmer B, Olthuis Wouter, van den Berg Albert
BIOS Lab-on-a-Chip Group, MESA+ Institute, Max Planck Center for Complex Fluid Dynamics, University of Twente, P.O. Box 217, AE Enschede, 7500, the Netherlands.
BIOS Lab-on-a-Chip Group, MESA+ Institute, Max Planck Center for Complex Fluid Dynamics, University of Twente, P.O. Box 217, AE Enschede, 7500, the Netherlands.
Biosens Bioelectron. 2021 Feb 1;173:112808. doi: 10.1016/j.bios.2020.112808. Epub 2020 Nov 10.
Since the industrial revolution 30% of the anthropogenic CO is absorbed by oceans, resulting in ocean acidification, which is a threat to calcifying algae. As a result, there has been profound interest in the study of calcifying algae, because of their important role in the global carbon cycle. The coccolithophore Emiliania huxleyi is considered to be globally the most dominant calcifying algal species, which creates a unique exoskeleton from inorganic calcium carbonate platelets. The PIC (particulate inorganic carbon): POC (particulate organic carbon) ratio describes the relative amount of inorganic carbon in the algae and is a critical parameter in the ocean carbon cycle. In this research we explore the use of microfluidic single-cell impedance spectroscopy in the field of calcifying algae. Microfluidic impedance spectroscopy enables us to characterize single-cell electrical properties in a non-invasive and label-free way. We use the ratio of the impedance at high frequency vs. low frequency, known as opacity, to discriminate between calcified coccolithophores and coccolithophores with a calcite exoskeleton dissolved by acidification (decalcified). We have demonstrated that using opacity we can discriminate between calcified and decalcified coccolithophores with an accuracy of 94.1%. We have observed a correlation between the measured opacity and the cell height in the channel, which is supported by FEM simulations. The difference in cell density between calcified and decalcified cells can explain the difference in cell height and therefore the measured opacity.
自工业革命以来，30%的人为排放的二氧化碳被海洋吸收，导致海洋酸化，这对钙化藻类构成威胁。因此，由于钙化藻类在全球碳循环中的重要作用，人们对其研究产生了浓厚兴趣。球石藻赫氏颗石藻被认为是全球最主要的钙化藻类物种，它由无机碳酸钙薄片形成独特的外骨骼。颗粒无机碳（PIC）与颗粒有机碳（POC）的比率描述了藻类中无机碳的相对含量，是海洋碳循环中的一个关键参数。在本研究中，我们探索了微流控单细胞阻抗谱在钙化藻类领域的应用。微流控阻抗谱使我们能够以非侵入性和无标记的方式表征单细胞的电学性质。我们使用高频与低频阻抗之比（称为不透明度）来区分钙化球石藻和因酸化而方解石外骨骼溶解的球石藻（脱钙）。我们已经证明，使用不透明度可以以94.1%的准确率区分钙化和脱钙的球石藻。我们观察到测量的不透明度与通道中细胞高度之间存在相关性，这得到了有限元模拟的支持。钙化细胞和脱钙细胞之间的细胞密度差异可以解释细胞高度的差异，进而解释测量的不透明度差异。
