Fluorescent Proteins: Biosensors

Fluorescent biosensors are proteins designed so that their fluorescent properties are sensitive to the presence of specific molecules or other factors. Most often, a conformational change in the sensing region of the construct leads to a change in signal of a circularly permuted fluorescent protein (cpFP) or Förster resonance energy transfer (FRET) efficiency of a pair of fluorescent proteins. Genetically encoded biosensors can be introduced into cells, tissues, or organisms for long-term imaging and can be designed to specifically localize to cellular compartments or organelles. Addgene’s database includes many fluorescent biosensors that signal the presence of specific biomolecules, the activity of specific genes and cellular processes, or other factors like environmental conditions.

With proper experimental design, biosensors can enable investigation of a signaling pathway or measurement of a biomolecule while largely preserving spatial and temporal cellular processes. Note that many of the articles linked below include variants with different binding affinities or negative-control constructs used to characterize the sensor's behavior in the target system. Use care when applying a biosensor in a novel context or modifying an existing construct, as fluorescence properties can be affected by environmental factors and the sensor behavior may differ from the original characterization (e.g. in vitro vs. in vivo, cytoplasmic vs. extracellular vs. organelle-localized).

Browse or search the tables below highlighting a few popular categories of biosensors or browse all the biosensors tagged in our catalog. Use the article links to find the plasmids associated with the article. We also offer ready-to-use AAV preparations of select plasmids; these are noted with the viral service icon .