Fluorescent labels for proteomics and genomics.

Fluorescent labeling reagents are an essential component of a huge industry built on sensitive fluorescence detection. This technology has grown over 30 years and is in some ways mature. Excellent labeling reagents with close to maximum theoretical brightness are available in many different colors. Large fluorescent proteins like phycobiliproteins are also widely used that are exceedingly bright. Other fluorescent proteins like the GFP family can be obtained for creating genetically encoded protein labels in living cells. A new 'solid state' quantum dot technology is being exploited for large-scale multiparameter labeling. This technology provides the 'ultimate' photostable labeling reagent. Still, there are advances to be made. Not available is the ultimate tool kit of low molecular weight, strongly light absorbing, photostable labels with narrow emission bands ranging from the UV to the IR.