Using “one-chip lab” technology, Stanford engineers have created a credit card-sized microlab that can detect COVID-19 In just 30 minutes.
During the epidemic, infectious disease specialists and frontline medical personnel have called for faster, cheaper and more reliable COVID-19 testing. Now, taking advantage of so-called “one-on-one chip” technology and cutting edge genetic editing technology known as CRISPR, Stanford researchers have created a highly automated device that can detect the presence of novel coronavirus in just half an hour. .
Juan G., senior author of the study. “A microlab is a half-sized microfluidic chip of a credit card with a complex network of channels smaller than the width of a human hair,” said a professor at the Charles Lee Powell Foundation in Santiago, Mechanical. Specialist in engineering and microfluidics at Stanford, a field dedicated to controlling liquids and molecules on a microscale using chips.
The new COVID-19 test is detailed in a study published in the journal November 4. Proceedings of the National Academy of Sciences. “Our tests can detect active infections relatively quickly and cheaply. It also does not rely on antibodies like many tests, which show whether someone is infected, and whether they are currently infected or not, ”said Ashwin Ramachandran, a Stanford graduate student and first author of the study.
Microlab testing takes advantage of the fact that coronaviruses such as SARS-COV-2, the virus of COVID-19, go everywhere behind small genetic fingerprints. RNA, Genetic precursor DNA. If the coronavirus RNA swab is present in the sample, the person from whom the sample was taken is infected.
To begin the test, the fluid from the nasal swab sample is placed in a microlab, which uses electric fields to extract and purify any nucleic acids, such as RNA. Then pure RNA DNA. Is converted into and then replicated several times using a technique called isothermal amplification.
Next, the team used an enzyme called CRISPR-K12S12 – a brother of the CRIRPR-K9S enzyme associated with this year’s Nobel Prize in Chemistry – to determine if any of the amplified DNA came from a coronavirus.
If so, the active enzyme triggers a fluorescent probe that causes the sample to glow. Here, too, electric fields play a crucial role in helping to concentrate all the vital components – target DNA, CRISPR enzymes and fluorescent probes – simultaneously dramatically increasing their chances in a space smaller than the width of human hair. Interaction.
“Our chip is unique in that it uses electric fields to purify both nucleic acids from the sample and accelerate chemical reactions, which tells us they are present,” Santiago said.
The team built its device on a shooting budget of about 5,000 5,000. For now, the DNA amplification step must be done outside the chip, but Santiago expects that within a month his lab will integrate all the steps into a single chip.
Some human-scale diagnostic tests use the same gene growth and enzyme techniques, but are slower and more expensive than the new test, providing results in just 30 minutes. Other tests may require more manual steps and may take several hours.
Researchers say their approach is not specific to COVID-19 and could be adapted to detect the presence of other harmful microorganisms, such as E. coli In food or water samples, or in tuberculosis and other blood diseases.
“If we were to discover a different disease, we would just form the right nucleus Acid Send the order to the computer and email it to the commercial manufacturer of the synthetic RNA. They reconcile a vial with a molecule that completely configures our continent for a new disease, ”Ramachandran said.
Researchers are working with Ford Motor Company to further integrate the measures and develop their prototype into a marketable product.
Reference: “Electric field powered microfluidics for rapid CRISPR based diagnostics and its diagnostic application SARS-CoV-2“By Ashwin Ramachandran, Diego A. Huke, Esha Sharma, Malay K. Sahu, Chunhang Nong Huang, Niaz Banai, Benjamin A. Pinski and Juan G. Santiago, November 4, 2020, Proceedings of the National Academy of Sciences.
DOI: 10.1073 / PNAS.2010254117
