Donor Quenching
Donor Quenching - Related Videos
10:57
Quenching and Boiling
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2023
Source: Alexander S Rattner, Sanjay Adhikari, and Mahdi Nabil; Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA Controlled heating followed by rapid cooling is an important element of many materials processing applications. This heat-treating procedure can increase material hardness, which is important for cutting tools or surfaces in high wear environments. The rapid cooling stage is called quenching, and is often performed by immersing...
07:17
Single Port Donor Nephrectomy
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Cited by 5 •
2011
Single port laparoscopic surgery is changing the standard of care in surgical care like nothing since the laparoscopic technique was introduced 20 years ago. We present out technique of single port donor nephrectomy using the Gelpoint device. We have successfully performed this surgery in 100 patients.
07:47
Anti-virulent Disruption of Pathogenic Biofilms using Engineered Quorum-quenching Lactonases
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Cited by 7 •
2016
Quorum-quenching enzymes are anti-virulent and anti-bacterial options that can mitigate pathogenesis without risk of incurring resistance, by preventing the expression of virulence factors and genes associated with antibiotic resistance and biofilm formation. In this study, we report a method that demonstrates the efficacy of quorum-quenching enzymes in bacterial biofilm disruption.
12:13
Ex Situ Normothermic Machine Perfusion of Donor Livers
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Cited by 21 •
2015
Here we present a protocol describing oxygenated ex situ machine perfusion of donor liver grafts. This article contains a step by step protocol to procure and prepare the liver graft for machine perfusion, prepare the perfusion fluid, prime the perfusion machine and perform oxygenated normothermic machine perfusion of the liver graft.
08:58
Cerebral Blood Oxygenation Measurement Based on Oxygen-dependent Quenching of Phosphorescence
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Cited by 27 •
2011
We present an experimental procedure for measuring the partial pressure of oxygen (pO2) in cerebral vasculature based on oxygen-dependent quenching of phosphorescence. Animal preparation and imaging procedures were outlined for both large field of view CCD-based imaging of pO2 in rats and 2-photon excitation based imaging of pO2 in mice.
FAQs
When a donor fluorophore reaches its excited state, a nearby acceptor can receive that energy through a nonradiative transfer pathway instead of allowing the donor to emit normally. This rerouting lowers donor fluorescence and provides an optical signal associated with the proximity of the interacting fluorescent partners in biological measurements.
Three factors are especially important: donor–acceptor distance, spectral overlap, and molecular orientation. Quenching becomes stronger when the fluorophores are closer, while the extent of transfer also depends on how well the donor emission and acceptor absorption correspond and how the molecules are oriented relative to one another.
Donor intensity and donor lifetime provide two related ways to detect the excited-state changes caused by energy transfer. Measuring the loss of intensity shows reduced emission, whereas lifetime measurements track how long the donor remains excited. Together, these readouts can support estimates of nanoscale proximity and molecular interaction.
Researchers can compare donor fluorescence before and after an interacting acceptor or quencher is present, focusing on the resulting loss of donor intensity. They may also measure donor lifetime. These observations provide quantitative evidence for altered donor behavior and can be used to estimate the proximity of labeled molecular components.
The distance sensitivity of donor quenching makes it useful for biosensor design. A biological event that changes the arrangement of donor and acceptor molecules can produce a measurable change in donor fluorescence or lifetime. This allows sensor systems to report molecular interactions or structural rearrangements through an optical signal.
In protein studies, changes in donor quenching can indicate altered proximity between labeled regions or interacting partners, helping identify conformational changes. The same principle can detect enzymatic activity when enzyme action changes the donor–acceptor relationship. Live-cell imaging extends these measurements to biological processes in cellular settings.