Mediator Probe PCR is a powerful and robust real-time PCR technology for multiplex DNA detection and quantification. It uses label free mediator probes, for molecular detection of nucleic acids during DNA amplification, in combination with fluorogenic universal reporters for signal generation. During PCR, target sequence specific mediator probes are cleaved by the polymerase and a generic sequence, the mediator, is set free. In the second step the mediator binds to the universal reporter, where it is extended by the polymerase. This generates a strong fluorescence signal increase. Due to the separation of DNA detection and signal generation many advantages arise. Mediator probes are not limited in their design by properties of the target sequence and a standard set of highly optimised fluorogenic universal reporters can be used for multiplex Mediator Probe PCR, right from the start.1
In the last years Mediator Probe PCR evolved from an innovative new method to an optimised and robust multiplexing technology. This was achieved by systematic characterisation of its molecular processes, which again was advantaged by the separation of DNA detection and signal generation. A design of experiments (DoE) approach was used for the optimisation of Mediator Probes, focusing on their binding strengths.2 In parallel, a set of universal reporters with improved signal-to-noise ratios was established by successive testing over 40 molecular structures, with different fluorophore-quencher labels and configurations.1
As a result, distinct guidelines exist, which enable fast adaption of new DNA targets and facilitate multiplex Mediator Probe PCR design. The capability of the technology was shown by highly sensitive, precise and specific multiplex Mediator Probe real-time PCRs in different areas of molecular diagnostics. These fields include monitoring of oncological disease, detection of pathogens or analysis of food samples.1,3
1. Lehnert M, Kipf E, Schlenker F, Borst N, Zengerle R, von Stetten F. Fluorescence signal-to-noise optimisation for real-time PCR using universal reporter oligonucleotides. Anal. Methods. 2018;10:190. doi: 10.1039/C8AY00812D.
2. Wadle S, Lehnert M, Rubenwolf S, Zengerle R, von Stetten F. Real-time PCR probe optimization using design of experiments approach. Biomolecular detection and quantification. 2016;7:1–8. doi: 10.1016/j.bdq.2015.12.002.
3. Wadle S, Lehnert M, Schuler F et al. Simplified development of multiplex real-time PCR through master mix augmented by universal fluorogenic reporters. BioTechniques. 2016;61(3):123–8. doi: 10.2144/000114443.