Armored Technology™: Armored® RNA
Armored RNA are Excellent Controls for Molecular Diagnostics
As molecular diagnostics has become part of routine clinical laboratory testing for the diagnosis and monitoring treatment of patients infected with RNA viruses such as HIV, HCV, and enterovirus, etc., there has developed a need for stable controls for clinical viral testing.
In developing RNA-based tests for these viruses, laboratories have incorporated positive controls and/or standards from one of three sources: In vitro transcribed RNA, positive patient specimens or commercially available viral preparations (attenuated/inactivated viruses).
However, none of these formats is ideal because of the following concerns:
- Ribonucleases are ubiquitous and can cause RNA degradation
- Incompatibility with plasma or serum matrix
- Viral preparations can have genetic heterogeneity and lot-to-lot inconsistency
- Unstable at ambient temperature
- Risks associated with infectious agents
- Some viruses are difficult to culture (e.g. HCV)
- More difficult to use patient specimens in the U.S. after introduction of new “HIPAA” regulations for protection of patient privacy
To control for potential failures of sample preparation and assay performance in viral RNA testing, novel Armored RNA controls were developed. The coat protein of Escherichia coli bacteriophage MS2 was used to package RNA fragments encoding target-specific viral sequences such as HIV and HCV.
The main advantage of Armored RNA controls is that the packaged RNA is stable and ribonuclease-resistant in plasma and other matrices. The RNA is compatible with any RNA-based clinical assay after sample extraction.
Armored RNA controls are ideal as sample extraction controls because they can be added directly to patient samples without risk of being degraded by nucleases in the sample. Thus, if the target RNA is degraded, or if enzymatic inhibitors are co-purified with the target RNA, then a lower than expected result will be obtained for the control RNA, alerting the laboratorian to a potential problem.
The important benefits offered by Armored RNA controls have been recognized by clinical laboratories using the controls within routine clinical testing as well as by major diagnostics companies, which have incorporated Armored RNA into in vitro diagnostic products.
 |
 |
| Features: Non-Infectious Well-characterized sequence Known input copy number (Armored RNA Quant) |
Features: Infectious Heterogenous sequence Variable stability among viruses |