exsig™ COVID-19 Direct
In vitro Real-Time PCR diagnostic test for Coronavirus COVID-19
- FDA Approved, CE Approved, Clinical Use Certified, EUA
- 96 patient samples kit format
- Lyophilized & Stable; Ready-to-Use
- Field-Tested, Currently in use globally
Cat.No. NGS-PD 001
Summary and Explanation
An outbreak of pneumonia of unknown etiology in Wuhan City, Hubei Province, China was initially reported to the World Health Organization (WHO) in December 2019. Chinese authorities identified a novel coronavirus SARS-CoV-2 (previously called 2019-nCoV) which has resulted in confirmed human infections worldwide and cases of COVID-19 disease. Symptoms of COVID-19 disease include severe respiratory illness and has resulted in the death of patients. Patients can become infected with the SARS-CoV-2 virus by person-person contact (through contact with a contaminated environment or person).
The exsig™ COVID-19 Direct (CE IVD) assay is a combination of a ‘direct to PCR’ sample processing method and a molecular in vitro diagnostic test for the detection of the SARS-CoV-2 RNA from nasopharyngeal and oropharyngeal dry swabs or swabs in PBS. The viral RNA is released from the swab sample via the addition of a viral inactivation/lysis agent. Following the sample preparation process, the resulting lysate is tested using well-established nucleic acid amplification technology. The PCR assay contains oligonucleotide primers and dual-labeled hydrolysis probes, as well as control material, for use in Real-Time RT-PCR for the in vitro qualitative detection of SARS-CoV-2 RNA.
Principles of the Procedure
Viral RNA is released from nasopharyngeal or oropharyngeal dry swabs or swabs in PBS using the ‘direct to PCR’ exsig™ COVID-19 Direct technology. Using polymerase chain reaction (PCR) technology, the RNA is reverse transcribed to cDNA and subsequently amplified using forward and reverse primers. A fluorescent-labeled probe is used to detect the amplicon. The probe system is based on the standard hydrolysis probe system known as TaqMan® Technology and the probes are labeled with a fluorescent reporter and quencher dyes.
During PCR cycling, the probe anneals to a specific target sequence located between the forward and reverse primers. The probe is cleaved by the 5’ nuclease activity of the Taq polymerase during the extension phase of the PCR cycle, causing the reporter dye to separate from the quencher dye, generating a fluorescent signal. With each PCR cycle, additional reporter dye molecules are released from the probe, increasing the fluorescence intensity. Fluorescence intensity is recorded at each cycle of the PCR by the Real-Time PCR machine.
The genesig® COVID-19 (CE IVD) assay is supplied as part of the exsig™ COVID-19 Direct (CE IVD) product. The genesig® COVID-19 (CE IVD) assay includes primers and probe mix which contains a SARS-CoV-2 specific probe labeled with the FAM fluorophore. The oligonucleotide primers and probes for the detection of SARS-CoV-2 were selected from the orf1ab genomic region. The primer and probe mix also includes primers and probes to amplify and detect the internal extraction control RNA template supplied (genesig® Easy RNA Internal Extraction Control (IEC)). The IEC specific probe is labeled with the HEX fluorophore.
The genesig® Easy RNA Internal Extraction control template is added to the sample during the exsig™ COVID-19 Direct (CE IVD) sample preparation to provide an RNA template control, detect PCR inhibition and confirm the integrity of the PCR run. The genesig® Easy RNA Internal Extraction control template is not related to the SARS-CoV-2 viral sequence.
PCR amplification has been validated using the following Real-Time PCR instruments: Applied Biosystems® 7500 Real-Time PCR System (software version 2.3), Roche® LightCycler 480 II (software version 126.96.36.199 SP3), Bio-Rad CFX Connect™ Real-time PCR Detection System (software 1.1), FluoroCycler® XT (FC XT 101, Bruker Hain Lifescience) and QuantStudio 5 (ThermoFisher Scientific, software v 1.4.3).
The exsig™ COVID-19 Direct assay is a CE marked, in vitro diagnostic test intended for the qualitative detection of nucleic acid from SARS-CoV-2 from nasopharyngeal and oropharyngeal specimens prepared on dry swabs or swabs in Phosphate Buffered Saline (PBS). The assay provides rapid screening of individuals suspected of SARS-CoV-2 infection and aids the diagnosis of suspected COVID-19 in patients. The assay is intended for use with the designated PCR platforms listed in Section 7.
SARS-CoV-2 is generally detectable in specimens during the acute phase of infection. Positive results are indicative of the presence of SARS-CoV-2 RNA. Positive results do not rule out co-infection with other bacteria or other viruses. Negative results do not preclude SARS-CoV-2 infection and should not be used as the sole basis for patient management decisions. Positive and Negative results must be combined with clinical observations, patient history, and epidemiological information.
The exsig™ COVID-19 Direct (CE IVD) assay is intended for use by qualified and trained clinical laboratory personnel specifically instructed and trained in handling SARS-CoV-2 positive samples and the techniques of real-time PCR and in vitro diagnostic procedures.
Specimen test results are available to interpret in under 2 hours using the exsig™ COVID-19 Direct (CE IVD) assay. This time includes the processing of the swab sample, the PCR set-up, and the PCR run time.
For Use with:
|Sample Types||Extraction Platforms||PCR Platform|
Direct (Extraction Only)
|Applied Biosystem® 7500
Bio-Rad CFX Connect™
Roche® LightCycler 480 II
FluoroCycler®XT (Bruker Hain Lifescience)
QuantStudio 5 (Thermofisher Scientific)
The exsig™ COVID-19 Direct (CE IVD) assay is comprised of the following two packs:
Pack 1: exsig™ COVID-19 Direct sample preparation pack
|Reagent label||Number of Vials 96 tests||Volume (ml per vial)||Lid colour||Resuspended with:|
|exsig™ Sample Preparation Buffer (small vial)||1||9.45||Green||n/a|
|exsig™ Sample Preparation Buffer (large vial)||1||113.4||White||n/a|
|Viral Inactivation Buffer||1||1.12||Yellow||n/a|
The exsig™ Sample Preparation Buffer is provided in 2 separate vials (small and large). The large vial should be designated to the sample lysis area; it is not required for swabs transported in media. The small vial is intended to be used for the sample dilution step (see section 14.2).
Pack 2: genesig® Real Time PCR Coronavirus (COVID-19) CE IVD assay
|Reagent label||Number of Vials 96 tests||Volume (μl per vial)||Lid colour||Resuspended with:|
|oasig™ OneStep 2X RT-qPCR Master Mix Lyophilised||2||525*||Red||oasig™ resuspension buffer|
|COVID-19 Primer & Probe Mix (including IEC primer & probe mix)||2||110*||Amber||Template preparation buffer|
|oasig™ resuspension buffer||2||750||Blue||n/a|
|Template preparation buffer||2||1500||Yellow|
|Water RNase/DNase Free||1||1500||White|
|genesig® COVID-19 Positive control template||1||600*||Red, vial stored in sealed foil pouch||Template preparation buffer|
|genesig® Easy RNA Internal extraction control (IEC)||2||1000*||Blue, vial stored in sealed foil pouch||Template preparation buffer|
The oasig™ OneStep 2X RT-qPCR Master Mix, COVID-19 Primers & Probes Mix, genesig® COVID-19 Positive control template and genesig® Easy RNA Internal extraction control (IEC) are all provided lyophilised. The table above indicates which buffer to use, as well as the volume to add, to resuspend these reagents.
Summary of Preparation and Testing Process