Fluorescent dyes

Fluorescent dyes are fluorophores that bind to specific cellular structures.

The following fluorophores are frequently used as fluorescent dyes:

• DAPI

• CY3 and CY5

• Rhodamine

• Fluorescein isothiocyanate (FITC)

In many cases, there is no fluorescent molecule that specifically binds to the cell structure to label. Therefore, fluorescent molecules are linked to another molecule that specifically binds to the cellular component to visualize. For instance, Phalloidin, a highly toxic molecule produced by a mushroom, binds to the actin cytoskeletons, prevents its depolarization, and thereby kills the cell. The high specificity to actin filaments can be used to stain the cytoskeleton by chemically cross-linking phalloidin with a fluorophore such as rhodamine.