Technical Summary

iFRET

• Excitation energy of a fluorescence donor is emitted by external energy, and a fluorescence donor of a fluorescence acceptor (adjacent to the fluorescence donor) is induced to emit fluorescence.
• Amino acids exhibiting the intrinsic fluorescence of a protein are used as the fluorescence donors.

Technical synopsis

• Probe for iFRET: (Target protein-specific binding site) + (iFRET fluorescence acceptor)
• Detecting and imaging a target protein by using a probe for iFRET
• Microscope device for iFRET

Technical Superiority

Conventional FRET

• External energy ⇒ A short-wavelength of a fluorescence donor emits excitation energy ⇒ Induce excitation of a long-wavelength of a fluorescence acceptor ⇒ emit fluorescence
• Required to label a target protein with a fluorescent substance (acting as a fluorescence donor).

Using intrinsic fluorescence of a target protein

 High sensitivity

• Fluorescence intensity is increased by 400 to 1000%.
• It is possible to analyze exactly the quantity, activity and mechanism of a protein.

High selectivity

• Specifically binding to a target protein.
• It is a technique to search for high-selectivity drugs

Biocompatibility

• Amino acids in a target protein are used as a fluorescence donor.
• There is no need to use a separate fluorescence label in the target protein.
• Metabolism disturbance and interference of cytophysiological factors are low.
• It is possible to monitor in vivo migration, activities and pathway of a protein, cell division and differentiation, etc. without destroying an organism.

Technical Data

Detection of a target protein Caspase-3

• Using a fluorescence acceptor alone ⇒ Fluorescence at approximately 445 nm
• Using Caspase-3 alone ⇒ Fluorescence at approximately 350 nm
• Using a fluorescence acceptor and Caspase-3 together ⇒ Increase in fluorescence at approximately 445 nm

Applications

• Trace the quantity, activity and action mechanism and migration path of a target protein.
• Characterize a protein.
• Screen drugs.
• Diagnose diseases (detect a disease-associated with the target protein).
• Detect food poisoning bacteria.