Compelling evidence is presented that sub-micron picoplankton shape, internal structure and orientation in combination leads to a disproportionate enhancement of differential forward scatter compared with differential side scatter when analyzed with a flow cytometer. Theoretical evidence is provided which results in an order of magnitude amplification in the forward scatter direction, with little or no change in the side scatter: this discounts the possibility of “doublets” caused by multiple particles simultaneously present in the laser beam. Observational evidence from progressively finer filtered seawater samples shows up to three orders of magnitude enhancement in the forward scatter direction and sizes of Prochlorococcus close to that reported in the literature (0.61 ± 0.17 µm). It therefore seems likely that flow cytometrically observed “bi-modal size distributions” of Prochlorococcus are instead the manifestation of intra-population differences in shape (spherical – prolate with preferential alignment) and internal structure (homogenous – heterogenous).

中文翻译：

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亚微米微型浮游生物的形状、方向和内部结构相结合，优先放大前向散射

提出了令人信服的证据，即当使用流式细胞仪分析时，亚微米微型浮游生物的形状、内部结构和方向相结合会导致差分前向散射与差分侧向散射不成比例地增强。提供的理论证据导致前向散射方向上的数量级放大，而侧向散射几乎没有变化或没有变化：这降低了由激光束中同时存在的多个粒子引起的“双峰”的可能性。来自逐渐过滤的海水样本的观察证据显示，前绿球藻的前向散射方向和大小增加了三个数量级接近文献中报道的 (0.61 ± 0.17 µm)。因此，流式细胞术观察到的原绿球藻的“双峰大小分布”似乎很可能是种群内形状（球形 - 长边优先排列）和内部结构（同质 - 异质）的表现。