A general strategy to red-shift green fluorescent protein based biosensors

Compared to green fluorescent protein (GFP) based biosensors, red fluorescent protein (RFP) based biosensors are inherently advantageous because of reduced phototoxicity, decreased autofluorescence, and enhanced tissue penetration. However, there is a limited choice of RFP-based biosensors and development of each biosensor requires significant effort. Herein, we describe a general and convenient method which uses the genetically encoded amino acid, 3-aminotyrosine (aY), to convert GFPs and GFP-based biosensors into red.