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Core Technology & Physics

31
Terms

Term Reference

31 terms
TermDescription
Acceptor Photobleaching Acceptor Photobleaching FRET FRET validation method where destroying the acceptor causes donor fluorescence to increase, confirming energy transfer w...
aFRET amplified FRET Amplified FRET using tyramide signal amplification to detect intramolecular activation states like kinase phosphorylatio...
Autofluorescence Tissue Autofluorescence Natural tissue fluorescence that creates background noise–overcome by lifetime-based FLIM detection.
Chromophore Fluorescent Molecule Light-absorbing molecule (like ATTO488 or Alexa594) that enables fluorescence detection and FRET measurements.
Dipole Orientation (κ²) Orientation Factor in FRET Factor (κ²) describing donor-acceptor dipole alignment; usually assumed " for random orientations.
Donor-Acceptor Pair FRET Donor-Acceptor Chromophore Pair Matched fluorophore pair (e.g., ATTO488/Alexa594) enabling FRET-based detection of molecular proximity.
Excited State Electronic Excited State (S₁) The higher-energy state (S₁) after photon absorption. Molecules relax via fluorescence, heat, or FRET—competition be...
Exponential Decay Fluorescence Exponential Decay The characteristic pattern of fluorescence fading over time: I(t) = I₀ × e^(-t/τ). FRET accelerates decay by providi...
FLIM Fluorescence Lifetime Imaging Microscopy Imaging technique measuring how long fluorophores remain excited–independent of concentration, enabling quantitative F...
FLIM-FRET Fluorescence Lifetime Imaging Microscopy with FRET Detection Combined technology using fluorescence lifetime measurement to quantify FRET–the foundation of QF-Pro functional bioma...
Fluorescence Lifetime tau (tau) Average time (typically 1–10 ns) a fluorophore stays excited before emitting a photon. Changes when FRET occurs.
Forster Radius R<sub>0</sub> = 5.83 nm (ATTO488/Alexa594) Distance at which FRET efficiency equals 50%–5.83 nm for ATTO488/Alexa594. Determines the effective detection range.
Frequency-Domain FLIM Frequency-Domain Fluorescence Lifetime Imaging FLIM technique using modulated excitation. Phase delay and demodulation of emission directly reveal fluorescence lifetim...
FRET Forster Resonance Energy Transfer Energy transfer between donor and acceptor molecules at 1–10 nm distances–the physics enabling detection of protein-...
FRET Efficiency E (Energy Transfer Efficiency) Percentage of energy transferred from donor to acceptor. Higher efficiency = closer proximity. Calculated from lifetime ...
Ground State Electronic Ground State (S₀) The lowest-energy state (S₀) of a fluorophore—the stable starting point from which photon absorption initiates excit...
iFRET immune-FRET Immune-FRET assay detecting checkpoint receptor-ligand engagement (e.g., PD-1/PD-L1) at molecular distances in FFPE tiss...
Immune Synapse Immunological Synapse The T cell–target cell interface where checkpoint receptor-ligand interactions occur at 1-10 nm distances detectable b...
IRF Instrument Response Function The instrument's own temporal response, which blurs lifetime measurements. Must be measured and accounted for in analysi...
Molecular Randomness Random, but Predictable Individual molecular events are random, but populations follow predictable statistical patterns—the basis for lifetime...
Phasor Plot Phasor Analysis / Universal Circle A fit-free graphical method for lifetime analysis. Decays transform to 2D coordinates; position reveals lifetime without...
QF-Pro Quantitative Functional Proteomics Platform HAWK Biosystems' patented FRET reagent kit — paired with the Violet 3.0 FLIM system and QF-Pro Software to quantify pr...
QF-Pro Applications & Clinical Evidence Comprehensive guide to QF-Pro validated applications across cancer types, checkpoints, and clinical contexts.
Quantum Yield Fluorescence Quantum Yield Fraction of absorbed photons re-emitted as fluorescence–affects brightness and FRET range.
Spectral Overlap Donor-Acceptor Spectral Overlap Integral The overlap between donor emission and acceptor excitation spectra that enables non-radiative energy transfer.
Stokes Shift Stokes Shift / Stokes Fluorescence Shift The wavelength difference between absorption and emission peaks, caused by energy loss during excited state relaxation. ...
Tau (τ) Fluorescence Lifetime Decay Constant The decay time constant extracted from stochastic photon events. Individual emissions are random; their collective histo...
TCSPC Time-Correlated Single Photon Counting Time-domain detection method that measures fluorescence lifetime by timing individual photon arrivals with picosecond pr...
Time-Domain FLIM Time-Domain Fluorescence Lifetime Imaging FLIM using pulsed excitation and photon timing (TCSPC) to directly measure decay curves. High precision, well-suited for...
TSA Tyramide Signal Amplification Enzyme-mediated signal amplification (10–100×) enabling FRET detection of low-abundance protein interactions in clini...
Violet 3.0 Violet 3.0 FLIM Platform HAWK Biosystems' benchtop FLIM platform—the hardware that enables QF-Pro functional proteomics in any laboratory.
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