Flow cytometric determination of size and complex refractive index for marine particles: comparison with independent and bulk estimates
Flow cytometric determination of size and complex refractive index for marine particles: comparison with independent and bulk estimates
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DOI：
10.1364/ao.42.000526
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发表时间：
2003-01-20
期刊：
影响因子：
1.9
通讯作者：
DuRand, MD
中科院分区：
文献类型：
--
作者：
Green, RE;Sosik, HM;DuRand, MD
本文提出了一种用流式细胞仪测量海洋颗粒物的前向散射、侧向散射和叶绿素荧光并结合Mie理论来确定其直径D和复折射率（n + n 'i）的方法。为了更好地理解Mie理论及其假设在流式细胞术（FCM）测量浮游植物细胞中的应用，我们评估。我们的流式细胞仪米氏（FCM-Mie）的方法，通过比较各种浮游植物培养的结果与独立的估计细胞D和估计的n和n'从散装测量反演。最初从FCM-Mie方法估计的单元D低于独立估计，并且n和n'通常高于整体估计。这些差异反映了较低的前向散射和较高的侧散射单细胞测量比米氏理论预测。经验散射校正的应用提高了FCM-米氏估计的细胞大小，n，和n ';值得注意的是，大小准确地确定在高和低光条件下生长的细胞，和n'与细胞内叶绿素浓度。浮游植物和矿物颗粒的结果的比较表明，这些颗粒类型之间的差异，可以确定从FCM测量。在应用到颗粒的天然混合物，真核皮科/nanophytoplankton和Synechococcus有最小的平均值n'在表面沃茨，和nonphytoplankton颗粒有较高的值n比浮游植物在所有深度。(C)2003年美国光学学会。
We advance a method to determine the diameter D and the complex refractive index (n + n'i) of marine particles from flow cytometric measurements of,forward scattering, side scattering, and chlorophyll fluorescence combined with Mie theory. To understand better the application of Mie theory with its assumptions to flow cytometry (FCM) measurements of phytoplankton cells, we evaluate. our flow cytometric-Mie (FCM-Mie) method by comparing results from a variety of phytoplankton cultures with independent estimates of cell D and with estimates of n and n' from the inversion of bulk measurements. Cell D initially estimated from the FCM-Mie method is lower than independent estimates, and n and n' are generally higher than bulk estimates. These differences reflect lower forward scattering and higher side scattering for single-cell measurements than predicted by Mie theory. The application of empirical scattering corrections improves FCM-Mie estimates of cell size, n, and n'; notably size is determined accurately for cells grown in both high- and low-light conditions, and n' is correlated with intracellular chlorophyll concentration. A comparison of results for phytoplankton and mineral particles suggests that differences in n between these particle types can be determined from FCM measurements. In application to natural mixtures of particles, eukaryotic pico/nanophytoplankton and Synechococcus have minimum mean values of n' in surface waters, and nonphytoplankton particles have higher values of n than phytoplankton at all depths. (C) 2003 Optical Society of America.