Fluorescent dyes are biological molecules that are made up of at least one fluorophore, which is a molecule that emits light on excitation by light energy. 

• Offer higher specificity and sensitivity
• Can be used to label live as well as fixed cells
• Can be used to localize and track specific cellular components
• Photostable and long-lasting
• Can be multiplexed for labeling multiple targets simultaneously 
• Can be used for quantitative analysis
• Compatible with multiple imaging techniques