Department of Chemical Science and Engineering, National Institute of Technology, Miyakonojo College, Miyakonojo, Japan.
Sci Rep. 2018 Mar 21;8(1):4967. doi: 10.1038/s41598-018-23311-8.
Microalgae have attracted attention for several industrial applications, but all such applications demand culture quality because of their sensitivity to environmental changes. Although simplicity, speed, and accuracy are important to assess algal cultures, researchers have expended vast amounts of labor to monitor algal health using hemocytometry. Along with its user bias, quantifying the cell status aside from the cell density is not easy. This paper describes the easy and rapid evaluation of algal number and status using an image-based cell counter (Countess II FL; Thermo Fisher Scientific Inc.) with a fluorescent filter for chlorophyll. Unlike mammalian cultured cells larger than microalgae, it is not easy for a low-resolution camera alone to distinguish microalgae from grimy spots and microbubbles on counting plates. To assess this method's performance, freshwater/marine microalgae and environmental samples were evaluated using the instrument. Results reveal that an instrument with a fluorescence filter can distinguish microalgae from other particles more precisely than a device with no filter. Values obtained using the instrument were not significantly different from those obtained using hemocytometry. Moreover, the cell counter, but not hemocytometry, can qualify the algal status. Results demonstrate that this system, which has no user bias, can contribute to algal assessment.
微藻因其对环境变化的敏感性而引起了人们对其在多个工业领域应用的关注，但所有这些应用都需要培养物的高质量。尽管简单、快速和准确对于评估藻类培养物很重要，但研究人员已经花费了大量的劳动力来使用血球计数法监测藻类的健康状况。除了细胞密度之外，定量细胞状态不仅具有用户偏差，而且不容易实现。本文描述了一种使用基于图像的细胞计数器（Countess II FL；Thermo Fisher Scientific Inc.）和叶绿素荧光滤光片来快速、简便地评估藻类数量和状态的方法。与哺乳动物培养细胞相比，藻类细胞较小，因此，仅使用低分辨率相机很难将藻类与计数板上的污垢斑点和微气泡区分开来。为了评估该方法的性能，使用该仪器对淡水/海洋微藻和环境样本进行了评估。结果表明，与无滤光片的设备相比，带有荧光滤光片的仪器可以更精确地区分藻类与其他颗粒。该仪器获得的值与血球计数法获得的值没有显著差异。此外，细胞计数器而非血球计数法可以确定藻类的状态。结果表明，这种无用户偏差的系统可以促进藻类评估。
