QRET Technologies - Specialists in mTR-FRET assay technologies and nucleic acid extraction - Distributed in the UK by Caltag Medsystems

QRET Technologies

QRET Technologies, Inc. is a Turku, Finland, based manufacturer and provider of innovative technologies, reagents and turnkey tools for biological and biomedical research, research and development of pharmaceuticals and clinical diagnostics.

Their products and services focus on two technologies: modulated Time Resolved Förster Resonance Energy Transfer (mTR-FRET) based assays and reagents, and nucleic acid extraction technologies using QuickPick™ tools.

Modulated Time Resolved Förster Resonance Energy Transfer (mTR-FRET) assays and reagents

Does the background autofluorescence of your sample interfere with the fluorescent detection of the analyte that you are interested in? The TR-FRET technology could help you obtain the optimal signal-to-background ratio that you need.

QRET Technologies is the provider of lanthanide chelates for a range of assay applications. The special luminescent properties of lanthanides make them the ideal reagent for the detection of analytes in the complex environment of a biological sample.

Lanthanides possess a long lifetime (in the μs-ms range, larger than the lifetimes of more common organic fluorophores which are in the ps-ns range). This allows the detection of their luminescent signal after the autofluorescence of analytes/proteins/plastics/optics in the sample has decayed, a process known as time gating or time resolved luminescence.1

The general principle of time resolved luminescence

Figure 1. The general principle of time resolved luminescence.1

The large apparent Stoke shifts (difference between the maximum excitation and emission wavelengths of fluorophores) and the narrow emission bands of lanthanides also contribute to the improved sensitivity and resolution obtained when using lanthanide chelates for analyte detection, compared to more conventional organic fluorophores.

The short Stoke shifts in organic fluorophores like FITC can result in unwanted reabsorption of emitted photons

Figure 2. The short Stoke shifts in organic fluorophores like FITC (left, adapted from reference 2) can result in unwanted reabsorption of emitted photons, which is avoided when luminescent reagents with large stokes shifts, like lanthanide chelates (right), are used. The sharp emission bands of lanthanide chelates make them easily to distinguish from the broad emission bands of organic fluorophores.

The shortcoming of lathanides is their poor absorption intensities. However, this is easily solved by incorporating the lanthanide ion into a ligand containing a organic fluorophore, which have high absorption. The organic fluorophore in the ligand can transfer the lanthanide the energy it has absorbed after being irradiated with a light source. This process is known as the antenna effect and overcomes the problem of lanthanide's poor absorption intensities.

QRET's technology is based on modulated TR-FRET or mTR-FRET.

Conventional TR-FRET assays require two organic fluorophores or more to bind to the analyte of interest in close distance to the lanthanide for measuring its emission. However, with the mTR-FRET technology, only the lanthanide chelate and, therefore, only one binder is needed without the need for further labelling of the target. When the lanthanide chelate is free in solution, it interacts with a modulator that quenches its emission. However, upon binding to the analyte of interest, the modulator is removed providing the luminescence signal required for selective detection.

mTR-FRET vs TR-FRET technologies

Figure 3. mTR-FRET vs TR-FRET technologies.3

The current portfolio of QRET's assays focuses on GTPases and growth factors. Assays are homogeneous single-label concepts without labelling of target receptors in a high throughput format using 384 microtiter plates. These kits provide you with high sensitivity assays using a novel technology format. The plates can be read using standard plate readers.

QRET also offer services for assay development including labelling of proteins, small molecules, aptamers with lanthanide chelates and fluorochromes.

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mTR-FRET for protein aggregation and interaction detection

The Protein-Probe assay concept is revolutionizing biomedical research, due to its high sensitivity and ease of use. Using mTR-FRET as the detection technique, the Protein-Probe can detect protein (antibody) aggregation below 0.1% outperforming the sensitivity of existing technologies 100-fold. Protein-Probe external dye approach is also highly applicable to protein-ligand interaction studies providing a tool for biochemical studies without labelling of protein and ligand.

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mTR-FRET for virus particle counting

QRET Technologies has developed the first functional bulk method to count enveloped and non-enveloped viruses in a high throughput format. The method provides a simple mix-and-measure tool to count viruses using mTR-FRET detection.

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Nucleic acid extraction with QuickPick™

QuickPick™ nucleic acid extraction kits and QuickPick™ handheld tools provide high-quality nucleic acid isolation and purification based on magnetic particles. The kits are scalable and can be used both with automatic devices and hand-held tools.

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  1. Hagan, A. K.; Zuchner, T. Lanthanide-based time-resolved luminescence immunoassays; Anal Bioanal Chem; 2011: 400; 2847–2864
  2. Shams-Nateri, A.; Piri, N. Prediction of Emission Spectra of Fluorescence Materials Using Principal Component Analysis. COLOR research and application; 2015
  3. Härmä, H.; Rozwandowicz-Jansen, A; Martikkala, E.; Frang, H.; Hemmilä, I.; Sahlberg, N.; Fey, V.; Perälä, M.; Hänninen, P. A New Simple Cell-Based Homogeneous Time-Resolved Fluorescence QRET Technique for Receptor-Ligand Interaction Screening; SLAS Discovery; 2009; 14:8, 936-943


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