FRET Based Assays

IRDye^®Near-Infrared Fluorescence Resonance Energy Transfer
(NIR-FRET) Protease Substrate

The IRDye^® Near-Infrared Fluorescence Resonance Energy Transfer (NIR-FRET) Protease Substrate, Caspase-3, can be used for the detection of protease activity in NIR-FRET assays. The substrate has low intrinsic fluorescence due to self-quenching of the conjugated dye by IRDye QC-1 quencher. Upon proteolytic cleavage of the substrate, fluorescence increases can be detected on an Odyssey^® Infrared Imaging System, Odyssey Sa Infrared Imaging System or other imaging systems with near infrared detection capabilities.

LI-COR^® offers the NIR-FRET Protease Substrate, IRDye 800CW/QC-1 CSP-3.

• Caspases
  Caspases are a family of intracellular cysteine proteases that are vital in the process of apoptosis (programmed cell death). Caspase-3 functions as the most downstream executioner in the caspase-apoptosis signaling cascade⁵. Activation of Caspase-3 by upstream initiator caspases (Caspases 2, 8, 9) results in the final execution of cell death⁶. Insufficient or accelerated apoptosis is implicated in a variety of diseases such as cancer, immune system diseases and nervous system disease⁷.

  Cited in Johnson, CE et al. Features of programmed cell death in intact Xenopus oocytes and early embryos revealed by near-infrared fluorescence and real-time monitoring . Cell Death Differ. (2009).
  [more info]

Advantages:

• Subnanomolar enzyme detection

• NIR detection dramatically reduces background, scattering and interference from other compounds

• Suitable for high-throughput screening of enzyme activity

• Up to 61-fold fluorescence intensity enhancement upon digestion

• Inhibitor and drug candidate IC₅₀ measurement

• Excellent water solubility

Ordering Information: