At SCB, we work with a wide range of assays to study kinase activity and screen potential inhibitors. Many of these assays rely on fluorescence, a powerful and sensitive way to quantify enzymatic reactions.
But anyone who has run fluorescence assays long enough knows the frustration:
While fluorescence is sensitive, it is also noisy.
Common problems include:
– Autofluorescence from buffers, plates, and biological components
– Scattered excitation light leaking into the detector
– Signal decay and photobleaching over time
– High well-to-well variability
Which makes it hard for us to trust small signal-changes, especially when screening inhibitors or generating dose-response curves. You end up spending a lot of time optimizing assays, repeating experiments or questioning whether an observed effect is real.
However, the solution may be as subtle as changing what we measure during fluorescence.
Instead of measuring how intense the fluorescence is, we measure how long the fluorescence persists!
You see, different fluorophores, even with similar wavelengths, can greatly vary in how quickly they fluoresce after absorbing light. For many noise sources and biological fluorophores, this is on the order of nanoseconds.
However, if we use chelated heavy metals as fluorophores, these have lifetimes of microseconds to milliseconds.
If we excite a sample with a short pulse of light:
Background autofluorescence and scattered excitation light appear immediately, but die out almost instantly
The lanthanide fluorophore, however, continues emitting long after the background has vanished just like the picture below.
Time drowns out the noise from our signal. This is the essence of time-resolved fluorescence (TRF).
Once fluorescence noise is suppressed in the time domain, binding-based measurements, such as FRET, become dramatically cleaner and more reliable.
This principle underlies the SwiftFluo® TR-FRET kinase kits. By combining long-lived lanthanide donors with time-gated detection, background autofluorescence and short-lived optical artifacts decay away long before detection begins. What remains is a clean, reproducible TR-FRET signal that directly reflects substrate phosphorylation and kinase activity.
In addition, the homogeneous, wash-free assay format eliminates multiple incubation and washing steps required by methods such as ELISA. This simplifies workflows, shortens assay time, and reduces sample and reagent consumption, making the platform well suited for both routine kinase studies and high-throughput screening.
To learn more about SwiftFluo® TR-FRET kits and their applications in kinase assays, protein–protein interactions, GPCR signaling, and drug screening, visit:
👉 https://www.sinobiological.com/other-products/swiftfluo-tr-fret-tks-kinase-kit-sfka001
