MicrosensDx is committed to providing customers with the most appropriate test to detect SARS-CoV-2 (COVID-19).
Throughout our 20-year history of developing diagnostics, our philosophy has been to remain test agnostic and to provide the most clinically appropriate testing solution on a case-by-case basis.
Our proprietary MicrosensDx RapiPRO™ SARS-CoV-2 Loop-mediated Isothermal Amplification (LAMP) test is in the final stages of clinical validation and can run on multiple platforms to detect SARS-CoV-2.
Loop-mediated Isothermal Amplification (LAMP) and polymerase chain reaction (PCR) tests both target the viral RNA of a sample. The nucleic amplification which both involve, enables detection of COVID-19 from samples with even a low viral load. This offers far greater accuracy and sensitivity than antigen testing for SARS-CoV-2s.
LAMP and PCR tests can detect COVID-19 from nasal swabs in both symptomatic and asymptomatic patients.
PCR testing has been one of the most widely used techniques in molecular biology for almost 30 years. In the detection of COVID-19, RT-PCR was the first established standard method by which other tests were compared to.
RNA from a suspected SARS-CoV-2 sample is first isolated using chemicals to remove proteins, fats, or other molecules from the sample. The RNA is converted into DNA in a process called reverse transcription (RT) before amplifying it to create millions of copies to detect. This requires enzymes to be repeatedly cycled through 3 temperatures, in a process known as thermocycling.
Fluorescent markers are added to the amplified DNA and produce light, enabling a machine to determine the test result. Once the intensity of light passes a defined threshold, a positive result is recorded. This process can involve up to 38 temperature cycles and the number of cycles needed to pass the fluorescence threshold is indicative of the viral load of the patient sample.
It must be carried out by laboratory technicians with extensive training and using specialist equipment. The process can return a result in a matter of hours.
LAMP is a newer method of testing using nucleic amplification which is growing in use as it is comparatively more efficient and cost-effective than PCR testing.
MicrosensDx is a pioneer of the technology, having used it in several of our clinically validated tuberculosis diagnostic products.
Like PCR, LAMP testing requires the RNA to be extracted from the sample before being amplified. It utilises the RapiPREP® system which employs highly efficient magnetic bead-based technology to extract and prepare the sample, removing the need for ethanol and other chemicals. This method of extraction markedly increases the sensitivity of the test.
The ‘loop-mediated’ in RapiPRO™ LAMP refers to the strand displacement which occurs to the RNA during the process, resulting in a loop. This loop structure facilitates the exponential accumulation of additional double-stranded DNA, producing it more quickly than PCR testing.
LAMP amplification also depends on heat, but it does not require multiple temperature cycles, with the process carried out isothermally, at around 60-65 0C.
This removes the need for expensive thermal cycling machinery and greatly reduces the time required to return a result. The MicrosensDx RapiPro for SARS-CoV-2 LAMP test can return results in under 30 minutes.
The low heating requirements can be fulfilled by a range of basic simple cost-effective equipment; both in a high throughput facility – including those currently configured for PCR testing – or in a close to patient setting.
This makes LAMP ideal for use in on-site, minimally equipped labs, by technicians with relatively basic training.
The MicrosensDx RapiPRO™ LAMP for SARS-CoV-2 test has been successfully deployed on-site with customers in a range of settings, including on large industrial sites and in airports.
It works efficiently on several platforms, including Genie® II, Genie III and Genie ® HT – with the latter for use in high-throughput environments, with each enabling enabling up to eight, 16 or 96 samples to be analysed respectively.
MicrosensDx RapiPRO® LAMP is able to detect all of the current known variants of SARS-CoV-2 spike protein (S), including the South African (501.V2) and Brazilian variant (B.1.1.248). This has been confirmed by in silico analysis of the variant sequences.