DiO是一种亲脂性的荧光染料，可以用来染细胞膜和其它脂溶性生物结构。进入细胞膜后，DiO在整个细胞膜上扩散，最佳浓度时可以使整个细胞膜染色。DiO在进入细胞膜之前荧光非常弱，当与细胞膜结合后其荧光强度大大增强，被激发后可以发出绿色的荧光，具有很高的淬灭常数和激发态寿命。可以用标准的FITC滤光片检测。

DiO通常不会明显影响细胞的生存力，因此被广泛用于正向或逆向的，活的或固定的神经等细胞或组织的示踪剂或长期示踪剂（long-term tracer）。除了最简单的细胞膜荧光标记外，还可以用于检测细胞的融合和粘附，检测发育或移植过程中细胞迁移，通过FRAP（Fluorescence Recovery After Photobleaching）检测脂在细胞膜上的扩散，检测细胞毒性和标记脂蛋白等。

冰袋运输。产品-20 ºC干燥避光保存，有效期1年。

Q:染完细胞膜后，可以染细胞核吗？

A:可以。

Q:该系列探针是只标记细胞膜还是细胞所有的膜结构均会被染上颜色？

A:DiI/DiO/DiD 和 DiR 是一种亲脂性膜染料，进入细胞膜后可以侧向扩散，逐渐使含有膜结构的细胞均被染色。

Q:DiO 和 DiR 的区别？

A:荧光强度：DiO 染色荧光强度通常低于DiR；

固定细胞或组织：DiO 染色效果欠佳，DiR 染色效果较好；

荧光持续时间：DiR 持续时间较长。有反馈被 DiR 标记的肿瘤细胞在体外培养的条件下可以存活长达 4 周，在体内 15 天后依然有很强的荧光信号。

Q:先将细胞固定，再用 DiO 染色，发现细胞核和细胞质也全部染上，是什么原因？

A:有如下可能原因：

1.DiO 浓度过大，建议适当降低浓度；

2.DiO 染色时间过长，建议适当缩短时间；

3.使用其它不适当固定液会导致荧光背景较高，建议使用 4%多聚甲醛固定细胞；

4.产品购买时间过长，已过期；建议重新购买。

Q:使用DMSO配置DiO储存液时出现不能完全溶解的沉淀该如何处理？

A:按照说明书使用DMSO配置1～2 mM储存液时如出现明显不溶沉淀，需使用超声波助溶，条件参考：40kHz，50℃，时间1h左右。由于DiO在DMF中溶解度高于DMSO及乙醇，推荐使用DMF对DiO进行溶解，同样需要使用超声波助溶。

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