RenDx detection technology
Surface enhanced resonance Raman scattering (SERRS) - the detection technology behind the RenDx Multiplex Assay System - is a powerful, information rich analytical spectroscopic technique. Renishaw has applied this highly sensitive and selective tool to develop a new approach to nucleic acid detection.
The SERRS advantage
Fundamentally, SERRS involves the adsorbtion of a target sample onto a suitably roughened metal surface. In the RenDx assay system, this surface consists of aggregated silver nanoparticles. Laser light is then directed onto the sample, where it interacts and gains or loses energy depending on the nature and chemical identity of the target. The scattered light is collected and processed to produce a SERRS spectrum, a unique 'fingerprint', consisting of sharp peaks attributed to the specific molecular vibrations within a target analyte.
Improved multiplexing capability
The molecular specificity of this technique allows the spectra of individual targets to be discerned from a composite spectrum (where multiple targets are present). The figure here shows the determination of multiple individual dyes from a composite SERRS spectrum. For clarity, only three targets are shown here, but higher order multiplexing is easily achieved.
SERRS vs fluorescence
In the context of multiplex analysis, SERRS holds significant advantages over more traditional fluorescence techniques. In particular, the broad featureless peaks obtained through fluorescence - as a result of the adsorption-emission process that underpins this technology - make multiplex detection extremely difficult. The most significant problem is often the 'masking' of lower concentration species by the intense, dominant peak of a higher concentration target within the same sample.
The final stage of the RenDx assay involves the detection and identification, via SERRS, of dye labels directly associated with a target species within the relevant RenDx panel. Interpretation of SERRS spectra and identification of species present is carried out using an integrated software package. The user requires no knowledge of the technology and a full test report is generated in minutes.