Non-invasive screening tests for preventive healthcare

A closer look at Aqsens Health’s E-TRF

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E-TRF is an enhancement to Time Resolved Fluorescence that adds new capabilities to increase its accuracy, while also making it more versatile. Here is a closer look at the technology our E-TRF is based on and the ways in which we can apply it to develop new screening tests for different diseases. 


Time Resolved Fluorescence

In chemistry, fluorescence is defined as the ability of molecules to emit light after the molecule has first absorbed light. The time that the molecule produces light is called its fluorescence lifetime. Some molecules have a longer fluorescence lifetime than others. A series of 15 chemical elements referred to as lanthanides have a long fluorescence lifetime, which is why they are often used in TRF measurements. 

The long fluorescence lifetime of lanthanides means that the molecule’s fluorescence reaction lasts longer. This enables TRF measurement a bit later, after the fluorescence reaction has been triggered in the molecules by a flash of light in the TRF reader (referred to as excitation). When the measurements are made a little bit later, all background fluorescence has had time to die out and the TRF reader will only measure the fluorescence produced by the lanthanide label. This enables the very specific classification of different samples, which is why TRF is at the core of Aqsens Health’s Enhanced-TRF (E-TRF) method. 

Aqsens Health’s E-TRF –method

The Aqsens E-TRF method combines Time Resolved Fluorescence with proprietary chemical and biological (bacteriophages) modulators that interact with the sample molecules to create a unique fingerprint of the sample. This method ensures that the sample’s own possible fluorescence does not affect the measurement.  The fingerprint is formed from a combination of modulators that have been measured in the same sample. The sample’s TRF intensity is comparable with the sample’s properties or biomarkers, and the interaction between each modulator and the lanthanide label. 

For E-TRF analysis, in addition to the sample molecules and a modulator, a lanthanide label is added to the sample. Out of the 15 different fluorescent lanthanide chemistries, the E-TRF method uses Europium (Eu). Adding the label and modulators to the sample connects the interactions in the sample to the TRF-phenomenon, and makes the interactions visible and measurable outside the visible spectrum of light. The TRF-reader analyses the fluorescence signal of the sample, giving it a numeric value. 

By modifying the modulators and comparing the molecular fingerprints, Aqsens Health can use the E-TRF method to develop screening tests for a variety of different types of diseases from cancers to communicable diseases. The sensitivity of the method can be targeted towards specific properties of a sample by adjusting the modulator. This enables Aqsens Health to develop tests for very specific purposes.