Comparing LAMP vs PCR
PCR testing has been one of the most widely used techniques in molecular biology for almost 30 years. It’s known as the gold standard for molecular diagnostic since clinically validated.
DNA or RNA from a suspected sample is first isolated using chemicals to remove proteins, fats, or other molecules from the sample. In case of RNA extraction, it’s converted into DNA subsequently in a process called reverse transcription (RT) before amplifying it to millions of copies to diagnose. Enzymes are to be repeatedly cycled through three temperatures, in a process named thermo-cycling.
Fluorescent probes are attached to the amplified DNA and make light, enabling a device to determine the test result. Once the intensity of light passes a defined cut-off value, a positive result is recorded. This process can involve up to thirty-eight temperature cycles and the number of cycles needed to pass the fluorescence cut-off is indicative of the viral load of the patient sample.
The process must be carried out by laboratory technicians with specialized training and using specific equipment. And it takes about 3 hours to return a result.
LAMP stands for Loop-mediated Isothermal Amplification. It’s an innovative method of testing using nucleic acid amplification, which grows gradually in use as it is comparatively more efficient and cost-effective than PCR testing.
Same as PCR, LAMP testing requires the DNA or RNA to be extracted from the sample before being amplified. The methodology employs highly efficient magnetic bead-based technology to extract and prepare the sample, removing the need for ethanol and other chemicals. This process of extraction significantly increases the sensitivity of the test.
In terms of RNA reverse transcription, the ‘loop-mediated’ refers to the strand displacement which occurs to RNA during the process, resulting in a loop. This loop structure facilitates the exponential accumulation of additional double-stranded DNA, making it faster 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 60-65ºC.
This removes the need for expensive thermal cycling machinery and greatly reduces the time required to return a result, which takes within 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 and POC (point-of-care) test.
This makes LAMP ideal for use in on-site, minimally equipped labs, by technicians with relatively basic training.