2nd Generation Dual-Target

qPCR test for SARS-CoV-2 RNA1

 more convenience, no false positive results*, high sensitivity

*until 8th August 2020 no false positive results were observed by us or reported to us from our customers and partners

During the acute phase of the Covid-19 disease, the existence of virus-genome can be proven by reverse transcriptase PCR (RT-PCR).

Our assays are based on peer reviewed, published and thoroughly tested PCR primers and probes, both by the developing institutes and by us.  The assays can be performed on any standard qPCR machine. We could show that the broadly used E-gene assay can also detect nucleic acids that are not originating from viruses (see below) and have therefore replaced this assay with a new one, that was developed by the University of Frankfurt (Toptan and Widera et al. 2020).  Because of the wide application of the E-gene assay, we nevertheless offer it in addition to the new assay.

Dual-Target Triplex Assay1

The Triplex assay targets two highly specific regions on the SARS-CoV-2 genome and a human RNA specific target.

The human RNA target proofs, if all steps of the process have worked, from swab-RNA extraction via reverse transcription to the qPCR.

The kit consists of a master-mix, primers and probes as well as  a positive control for extraction and amplification.

A part of the the CoV-2 specific assay was designed by the virology department of the J.W.Goethe University of Frankfurt am Main (Toptan, Widera et al. 2020).

For Orders: please contact info@genxpro.de

Cat.Nr. 031522-M3x; 96 reactions

Dual Plex WHO Assay1

This single-plex assay corresponds to WHO assay as designed by the Charité / Drosten.

The test is performed in two steps using a highly sensitive E-gene assay followed by a more specific ORF-Gene assay. Each is performed in a separate qPCR tube.

The kit consists of a master-mix, primers and probes as well as  a positive control for extraction,  reverse transcription and amplification.

The CoV-2 specific assay was designed by the Charité, Berlin (Drosten et al. 2020).

For Orders: please contact info@genxpro.de

Cat.Nr. 031522-E2x; 96 reactions

Sensitivity

All tests detected the presence of approximately 10 RNA molecules per reaction*

Specificity

Problems of the WHO E-gene assay and false positives

The E-gene specific primers of the WHO assay have been reported to generate up to 10% false positives.

We sequenced a PCR product of a false positive sample and found a 70 bps long region matching to Neisseria subflava strains (see BLAST results of the amplicon below), a relatively common nasopharyngal bacterium.

The M-Gene Assay

Therefore, we adapted the M-gene assay (Toptan and Widera et al. 2020) for high specificity and potentially lower rates of false positives.

Samples that generated false positive results using the E-primers of the WHO/Charité assay were correctly found to be negative using our multiplex assays. The specificity was prior described by Toptan and Widera et al. 2020 and proven with samples that showed false positive results using E-Primers in our lab. We cannot exclude that our assay leads to false positives but this was not the case with samples that led to false positives with the E-gene (WHO) assay.

Pricing

Ouf prices depend on the type of test and on the number of samples.

For request please call +49 69 95739710 or send us an e-mail to info@genxpro.de

Reference:

Optimized qRT-PCR approach for the detection of intra- and extra-cellular SARS-CoV-2 RNAs

Tuna Toptan, Sebastian Hoehl, Sandra Westhaus, Denisa Bojkova, Annemarie Berger, Björn Rotter, Klaus Hoffmeier, Sandra Ciesek,  Marek Widera;

*testet on ABI-StepOne in 25 µl reactions.

1For Research use only