Scientists identify test that can diagnose Covid-19 samples in 30 minutes
The RT-LAMP technique is thought to be less expensive than the standard PCR testing currently being used.
A new test that can diagnose Covid-19 in just 30 minutes by analysing urine, blood or saliva samples has been identified by scientists.
The method, known as reverse transcription loop-mediated isothermal amplification (RT-LAMP), involves looking for genetic material, or RNA, of the coronavirus in the test samples.
RT-LAMP is a well-known technique that has been previously used to detect viruses such as Zika and Ebola.
Led by Laura Lamb, of Beaumont Health, a healthcare system in Michigan, US, the researchers said the main objective of their study was to look for a rapid screening diagnostic test.
The team conducted tests on simulated patient samples, which involved spiking dummy specimens with genetic material from Sars-CoV-2, as well as clinical samples, which contained the actual Sars-CoV-2 virus.
The samples were tested using RT-LAMP as well as by conventional PCR.
The RT-LAMP method was found to detect Sars-CoV-2 in all the dummy samples in within 30 to 45 minutes.
According to the researchers, the RT-LAMP was positive for 95% (19/20) of these samples and negative for 90% (18/20) of them, when compared with the PCR testing method.
The two samples that were positive by RT-LAMP but negative by the PCR testing could represent false positives, contamination, or increased sensitivity of RT-LAMP compared with PCR, the researchers said.
He said: “This study shows that the method can detect genetic material from Sars-CoV-2 when this was added to ‘dummy’ samples from volunteers in 19/20 cases.
“However, it also generated 2/20 false positives in negative samples.
“This may be due to cross-reactivity with other viruses or contamination during processing.
“When samples from Covid-19 patients were used (containing actual Sars-CoV-2 virus, rather than purified genetic sequences), it was less sensitive, detecting only 4/10 cases.”
