InActiv Blue
in the scientific literature
Viruses
Evaluation of Saliva as a Matrix for RT-PCR Analysis and Two Rapid Antigen Tests for the Detection of SARS-CoV-2, Viruses, De Meyer et al., 2022
Nature Biotechnology
A public–private partnership model for COVID-19 diagnostics Krijger, Hoek et al., Nature Biotechnology, 2021
medRxiv
Environmental circulation of adenovirus 40/41 and SARS-CoV-2 in the context of the emergence of acute hepatitis of unknown origin, medRxiv, Wollants et al., 2022
Biosensors and Bioelectronics
Molecular detection of SARS-COV-2 in exhaled breath at the point-of-need, Biosensors and Bioelectronics, Stakenborg et al., 2022
Journal of Pediatrics, Perinatology and Child Health
Equivalence of saliva RT-qPCR testing to nasal-throat/nasopharyngeal swab testing in the general practitioner’s setting to detect SARS-CoV-2 Jonckheere et al., Journal of Pediatrics, Perinatology and Child Health 6:042-053, 2022
Journal of Clinical Microbiology
Bos et al., 2023 Prospective Performance Evaluation of the miDiagnostics COVID-19 PCR Test for Rapid SARS-CoV-2 Detection on Nasopharyngeal Swabs
Acta Virologica
Detection of SARS-CoV-2 using a laboratory-developed ultra-fast NextGenPCR test versus a conventional RT-PCR test
Čurová et al., 2023
Virology Journal
Nationwide quality assurance of high throughput diagnostic molecular testing during the SARS CoV 2 pandemic: role of the Belgian National Reference Centre Janssen, Cuypers, Laenen et al., 2024
International Journal of Molecular Sciences
Assessment of DNA/RNA Defend Pro: an inactivating sample collection buffer for enhanced stability, extraction-free PCR, and rapid antigen testing of nasopharyngeal swab samples., Claeys et al., 2024
medRxiv
Evaluation of a novel respiratory virus inactivating buffer for parallel RT-qPCR and quick antigen testing., Deprez et al., 2024
ResearchGate
Investigating the impact of inactivating transport media on cell integrity in various pathogen classes
Koka and Wende, 2024
Preprints
Direct PCR for rapid and safe pathogen detection: field testing in emerging infectious disease outbreaks? Brukner and Oughton, 2025
eBioMedicine
Interpretation of indoor air surveillance for respiratory infections: a prospective longitudinal observational study in a childcare setting Geenen et al., 2025
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Frequently asked questions
General
A CE-marked In Vitro Diagnostic (IVD) device is a product that has been assessed and validated according to EU regulations, ensuring it meets required safety, quality, and performance standards. The CE mark indicates that the device is legally authorized for use in the European Economic Area (EEA) and can be marketed for the defined clinical diagnostic purposes. It did undergo rigorous testing and clinical validation, confirming that it delivers accurate results and fulfills the performance claims made by the manufacturer.
A Research Use Only (RUO) device is designed for laboratory or research purposes, not for diagnostic or clinical use. These devices are not subject to the same regulatory oversight or performance validation required for clinical use, and the manufacturer does not make claims about their accuracy or suitability for patient diagnosis. RUO devices are strictly intended for non-regulatory research environments, and their use in clinical settings is prohibited.
For some buffers, InActiv Blue offers both a RUO version and an IVD version.
DNA/RNA DefendTM
RNAwaitTM and RNAlater® are ammonium sulfate RNA stabilization buffers for tissue. The chemical composition, the performance, and the intended use differ from our DNA/RNA Defend buffer. The table below highlights key differences between DNA/RNA DefendTM and these other buffers.
| DNA/RNA DefendTM | RNAwaitTM | |
| active ingredient | guanidinium thiocyanate | ammonium sulfate |
| pathogen inactivation | wide range of pathogens are completely inactivated, making it safe to work with the samples | NA |
| nuclease inactivation | irreversible | reversible |
| stabilization of RNA | more than a month at 37 °C (or room temperature or 4 °C) | 1 day at 37 °C, 1 week at room temperature, 1 month at 4 °C |
| CE-IVD status | the IVD version of RUO product DNA/RNA DefendTM has a blue color and is called InActiv Blue® | NA |
| biofluids | excellent performance on saliva, swab, urine | NA |
| lytic activity | guanidinium thiocyanate | NA |
| mucolytic activity | makes sputum and saliva less viscous | NA |
| histopathology compatibility | not tested yet, but unlikely because of lytic activity | yes |
Both buffers are innovative and proprietary stabilization buffers for biomaterials. The key differences are that DNA/RNA Defend ProTM is compatible with extraction-free workflows (e.g. direct PCR on stabilized sample) and allows antigen testing. See table below for more differences between these 2 types of sample stabilization.
| DNA/RNA DefendTM | DNA/RNA Defend ProTM | |
| extraction-free workflow | No. Stabilized samples must be extracted to obtain pure nucleic acids for downstream analyses | Yes. Stabilized sample can in general be directly used in e.g. (RT-)PCR reaction at 10% input. |
| antigen preservation | No. Antigens and other proteins are denatured. | Yes. Stabilized sample can be used for ELISA and quick antigen testing. |
| pathogen inactivation | wide range of virus, bacteria and yeast are completely inactivated, making it safe to work with the samples (+++) | all tested viruses and half of the tested bacteria are inactivated (++) |
| stabilization of RNA | more than a month at 37 °C (or room temperature or 4 °C) (+++) | 8 days at 4 °C, 2 days at room temperature (depending on sample type) (++) |
| CE-IVD status | the IVD version has a blue pipetting aid and is called InActiv Blue | NA |
| lytic activity | effective sample lysis buffer | mild lysis buffer |
| mucolytic activity | makes sputum and saliva less viscous (++) | makes sputum and saliva less viscous (+++) |
InActiv Blue is not only the name of our company, but also of our first CE-IVDR product. From a chemical perspective, DNA/RNA DefendTM and InActiv Blue® are identical, but InActiv Blue® has an inert blue dye as a pipetting aid and is CE-IVDR marked. While InActiv Blue® comes in automation-ready tubes with 2 mL of buffer, DNA/RNA DefendTM comes in larger plastic bottles of varying sizes.
DNA/RNA Defend ProTM
Both buffers are innovative and proprietary stabilization buffers for biomaterials. The key differences are that DNA/RNA Defend Pro™ is compatible with extraction-free workflows (e.g. direct PCR on stabilized sample) and allows antigen testing. See table below for more differences between these 2 types of sample stabilization.
| DNA/RNA DefendTM | DNA/RNA Defend ProTM | |
| extraction-free workflow | No. Stabilized samples must be extracted to obtain pure nucleic acids for downstream analyses | Yes. Stabilized sample can in general be directly used in e.g. (RT-)PCR reaction at 10% input. |
| antigen preservation | No. Antigens and other proteins are denatured. | Yes. Stabilized sample can be used for ELISA and quick antigen testing. |
| pathogen inactivation | wide range of virus, bacteria and yeast are completely inactivated, making it safe to work with the samples (+++) | all tested viruses and half of the tested bacteria are inactivated (++) |
| stabilization of RNA | more than a month at 37 °C (or room temperature or 4 °C) (+++) | 8 days at 4 °C, 2 days at room temperature (depending on sample type) (++) |
| CE-IVD status | the IVD version has a blue pipetting aid and is called InActiv Blue | NA |
| lytic activity | effective sample lysis buffer | mild lysis buffer |
| mucolytic activity | makes sputum and saliva less viscous (++) | makes sputum and saliva less viscous (+++) |
DRD Blood
The PAXgene Blood RNA system differs from DRD Blood in several ways. PAXgene requires a larger blood draw volume of 2.5 mL compared to DRD Blood’s 1 mL. It offers only one RNA extraction method, whereas DRD allows several choices. Additionally, RNA extraction from the same tube is impossible with PAXgene, whereas DRD permits multiple extractions. The tube size for PAXgene is larger at 16 x 100 mm compared to DRD’s 13 x 75 mm.
Regarding RNA stability, PAXgene normalizes Cq values (ΔΔCq), while DRD demonstrates stability using ΔCq values (comparing time points). Of note, normalization may mask instability issues. The stability criteria are more strict for DRD (<1.08 ΔCq) compared to PAXgene (<1.93-2.34 ΔΔCq). Molecular RNA stability at 4 °C is much shorter for PAXgene at 5 days, whereas DRD offers stability for 30 days; however, at 25 °C, both maintain RNA stability for 3 days. Physical RNA integrity at 4 °C and 25 °C is reported for DRD Blood (3 days and 1 day, respectively), while PAXgene does not provide this information.
Regarding RNA yield stability, DRD maintains a stable yield over time, whereas PAXgene experiences a decline. Freeze-thaw stability is greater for DRD (>5 cycles) than for PAXgene (2 cycles). Finally, PAXgene has a significantly higher list price than DRD.
| DRD Blood | PAXgene Blood RNA | |
| blood draw volume | 1 mL | 2.5 mL |
| RNA extraction methods | choice from several | 1 |
| RNA extraction repeats from same tube | several | none |
| tube size | 13 x 75 mm | 16 x 100 mm |
| RNA stability claim | ΔCq values (compared to T0) | normalized Cq value (ΔΔCq) |
| <1.08 ΔCq | <1.93-2.34 ΔΔCq | |
| molecular RNA stability 4 °C | 30 days | 5 days |
| molecular RNA stability 25 °C | 3 days | 3 days |
| physical RNA integrity 4 °C | 3 days | N/A |
| physical RNA integrity 25 °C | 1 day | N/A |
| RNA yield stability | yes | no (declines over time) |
| freeze thaw stability | >5 | 2 |
| list price | € | €€€ |
InActiv Blue®
InActiv Blue is not only the name of our company, but also of our first CE-IVDR product. From a chemical perspective, DNA/RNA Defend™ and InActiv Blue® are identical, but InActiv Blue® has an inert blue dye as a pipetting aid and is CE-IVDR marked. While InActiv Blue® comes in automation-ready tubes with 2 mL of buffer, DNA/RNA Defend™ comes in larger plastic bottles of varying sizes.
Nuclease-free water
Type 1 grade water, or ultrapure water, is the purest form of water produced by actively removing impurities. It’s used for the most critical applications and advanced analytical procedures. It comes with certified low levels of conductivity and endotoxins. On top of that, we control each lot to functionally guarantee the absence of nucleases.
An alternative method to produce RNase-free water is to treat it with DEPC (diethylpyrocarbonate) and then autoclave it to inactivate traces of DEPC. Unfortunately, remaining traces or byproducts may inhibit further biochemical reactions. Furthermore, chemical modification of RNA is possible when traces of DEPC or its byproducts are present, resulting in impaired recovery of intact RNA.
Deionized or demineralized water has been treated to remove all ions, but other impurities may remain present. When treating water in the lab (either via DEPC or demineralization), important lot quality control and verification of the absence of nucleases is typically not performed.
In conclusion, InActiv Blue’s nuclease-free water is the most convenient quality-controlled source of ultrapure water for all your applications.