scientist working with cells

Choosing a cell type for imaging

Cells perform a multitude of functions within an organism, and their shape is highly correlated with their function, so it should come as no surprise that cells have a broad variety of shapes and volumes, levels of specific protein expression, and metabolic activities.

Here is some guidance on choosing a cell type that will work well for the images you want to capture.

photograph of scientist working with cells in a sterile hood 

选择成像实验的细胞类型

细胞执行着生物体内的诸多功能，而其形态又与其功能密切相关，因此细胞具有各种各样的形状和大小、特定蛋白表达水平和代谢活性差异也就不足为怪了。

下面是一些细胞成像应用细胞类型挑选的基本原则。

Topics in this lesson

本节主要讨论


关于细胞功能及操作便利性

如果您的成像实验不必依赖某个特定的细胞类型，那么最好选择靶标易于成像的细胞类型。例如，如果您希望研究某一种蛋白质，则在细胞结构中大量表达该蛋白的细胞类型就是您的理想选择；如果您希望在现有的细胞背景内加入感兴趣的靶蛋白，则最好选择可以轻松转染该蛋白且在转染之后仍能保持良好健康状态的细胞类型。如果您希望标记参与代谢途径的某些物质/成分，最明智的做法就是选择具有稳健代谢反应的细胞类型。

Fibroblasts and epithelial cell lines can be good choices for cell structure staining

If you are studying the cytoskeleton, or other cellular structures in the cytoplasm like the Golgi complex, ER, or mitochondria, pick a cell line in which the nucleus does not predominate the volume of the cell. If the space between the nucleus and the plasma membrane is very small, it can be challenging to visualize cellular structures with fluorescence microscopy, as is the case with macrophage-derived cell lines such as RAW264.7 or MMMs. Cell lines derived from dermal fibroblasts are frequently imaged in wound healing studies because they exhibit robust filamentous actin that is easily stained and imaged. Epithelial-derived cell lines are popular for imaging cellular structures for several reasons: they are big enough that the nucleus doesn’t dominate the cell lumen; many show continuous actin filaments in a single focal plane; they are more physiologically relevant for many cancers than fibroblast-derived cell lines; and cell lines such as HeLa, A549, and MDCK are very well characterized, which gives the advantage of both proven protocols and a frame of reference for your experimental results.

Four-panel image composed of photographs

Figure 1. A549, HeLa, ME180, and U2OS cells all exhibit very different staining patterns for the same set of fluorescent reagents due to differences in their morphology and metabolic pathways. All four cell types were stained with NucBlue Live® reagent after transduction with CellLights®Golgi-RFP and Mito-GFP reagents.


纤维细胞和上皮细胞是细胞结构染色的良好选择

如果您正在研究细胞骨架或者高尔基体、内质网或线粒体等细胞质内的细胞结构，则最好选择细胞核不会占据细胞内较大体积的细胞系。如果细胞核和细胞质膜之间的空隙过小，则可能难以通过荧光显微镜观察到细胞结构，如RAW264.7或MMMs等巨噬细胞源细胞系。真皮成纤维来源的细胞系常常用于创伤愈合成像研究，这是因为它们可以表达稳定且可轻松染色和成像的 丝状肌动蛋白 。上皮来源的细胞则因为如下几个特点也使用率颇高：体积足够大，细胞核不会主导细胞内腔；在单个聚焦平面上可以显示连续的肌动蛋白微丝；相对于成纤维来源的细胞系，它们与多种癌症具有更多的生理学相关性；HeLa、A549和MDCK等细胞系特征鲜明，同时具有了已验证过的实验方案和可大量参考实验结果。

Four-panel image composed of photographs of A549, HeLa, ME180, and UTOS cells, each stained with a blue-fluorescent nuclear stain, a red-fluorescent Golgi body stain, and a green-fluorescent mitochondrion stain.

图1. 由于细胞形态和代谢途径的差异，使用同一组荧光试剂，A549、HeLa、ME180和U2OS细胞出现了差异极大的染色图案。先用CellLightsGolgi-RFP和Mito-GFP试剂转导，然后采用NucBlue Live试剂染色。


最终选择需综合考虑

BPAECs是一种内皮来源的细胞系，常常被用到，其细胞体积较大，形状扁平，很便于对细胞结构成像。但如果您希望对过度表达的蛋白质成像，那么这种细胞的转染效率就不够高。HEK293则相反，这种细胞广泛应用于转染研究，但由于其在培养表面无法非常紧密地附着，往往不能很好地成像——因为浮动的细胞很难成像。很多时候，我们不得不放弃那些在某一关键方面上最理想的细胞类型（因为其具有其他若干缺点），而选择那些能够多方面特性相对平均的细胞系（即便其在任何单个参数方面都不是最突出的）。

仅供科研使用，不可用于诊断目的。