紫外熒光蛋白UV Proteins

藍色熒光蛋白Blue Proteins

青色熒光蛋白Cyan Proteins

綠色熒光蛋白Green Proteins

黃色熒光蛋白Yellow Proteins

桔色熒光蛋白Orange Proteins

紅色熒光蛋白Red Proteins

遠紅熒光蛋白Far Red Proteins

近紅熒光蛋白Near IR Proteins

Sapphire-type Proteins

Red Fluorescent Proteins

Red fluorescent proteins (RFP) can be imaged on existing confocal or widefield microscopes, and they also have more penetrating power. The excitation and emission maxima of RFP are 558nm and 583 nm, respectively.

The use of RFP, however, has been hampered with several issues. RFP is an obligate tetramer - thus, it forms large aggregates inside cells. This makes the use to RFP to report the location of a protein severely limited.

Although GFP can successfully fuse with several hundreds of proteins, RFP-conjugated proteins are often toxic. Some variants of RFP have overcome these limitations. For example, DsRed2 fluorescent protein does not form aggregates and has reduced toxicity, while another variant of RFP (known as RedStar) has increased brightness and maturation rate.