Portable, point-of-care COVID-19 test could bypass the lab, study finds
Source: University of
Illinois at Urbana-Champaign, News Bureau
Researchers have demonstrated a prototype of a
rapid COVID-19 molecular test and a simple-to-use, portable instrument for
reading the results with a smartphone in 30 minutes, which could enable
point-of-care diagnosis without needing to send samples to a lab.
COVID-19 continues to spread, bottlenecks in supplies and laboratory personnel
have led to long waiting times for results in some areas. In a new
study, University of Illinois, Urbana-Champaign researchers have demonstrated a
prototype of a rapid COVID-19 molecular test and a simple-to-use, portable
instrument for reading the results with a smartphone in 30 minutes, which could
enable point-of-care diagnosis without needing to send samples to a lab.
“If such a device and test were available, we could
test for COVID-19 at public events, auditoriums, large gatherings and
potentially even at home for self-testing. The results could be sent back to
the appropriate public health system for coordination,” said Rashid
Bashir, a professor of bioengineering and the dean of the Grainger College of
Engineering at Illinois. Bashir co-led the study with electrical and computer
engineering professor Brian Cunningham and mechanical science and engineering
professor Bill King.
Typical tests for SARS-CoV-2, the virus that causes
COVID-19, take a sample from a patient with a long nasopharyngeal swab, put
that swab into a substance called viral transport media, and send it to a lab
for a multistep process of extracting, isolating and multiplying the telltale
RNA inside the virus. This RNA multiplication process, called RT-PCR, requires
several temperature fluctuation cycles, specialized equipment and trained
personnel, Cunningham said.
As reported in the Proceedings of the National Academy
of Sciences, the Illinois team used a simpler process to analyze the viral
transport media, called LAMP, which bypasses the RNA extraction and
“LAMP only needs one temperature — 65 C — so it is
much easier to control,” said graduate student Anurup Ganguli, the first
author of the study. “Also, LAMP works more robustly than PCR, especially
when there are contaminants in the test sample. We can just briefly heat the
sample, break open the virus and detect the genetic sequence that specifically
The researchers compared the LAMP assay with PCR, first
using synthetic nasal fluid spiked with the virus and then with clinical
samples. They found the results were in agreement with PCR results, and they
documented the sensitivity and specificity of the LAMP test.
Then, the researchers incorporated the LAMP assay onto a
small 3D-printed microfluidic cartridge that has two input slots for syringes:
one for the sample-containing viral transport media, one for the LAMP
chemicals. Once the two are injected, they react within the cartridge.
“We use modern, high speed additive manufacturing to
make these cartridges. The entire thing can be quickly scaled up to hundreds of
thousands of tests,” King said. “Production scale-up is typically the
biggest obstacle for commercial applications of microfluidic cartridges, and we
can overcome that obstacle using this new approach. Modern additive
manufacturing is elastic and scalable, and it can be ramped up very quickly
compared with legacy manufacturing technologies.”
The team is working with Fast Radius Inc., a Chicago-based
technology company King co-founded, to manufacture the microfluidic cartridges.
The cartridge can be inserted into a hand-held portable
instrument with a heating chamber, which heats the cartridge to 65 degrees
Celsius for the duration of the reaction, and a smartphone cradle for reading
the results. In approximately 30 minutes, a positive result will emit
“The reader illuminates the liquid compartments with
light from blue LEDs, while the phone’s rear-facing camera records a movie of
the green fluorescent light being generated,” Cunningham said.
The researchers demonstrated the portable device with
additional clinical samples, and found the results matched those of the
standard PCR lab procedure.
The researchers are exploring whether the assay would work
with saliva samples to eliminate the need for nasopharyngeal swabs, and
collecting more patient data as they consider next steps for regulatory
approvals, Bashir said.
The National Science Foundation, the National Institutes of
Health and the Defense Advanced Research Projects Agency supported this work.
Clinical samples were obtained from OSF HealthCare in collaboration with Dr.
Sarah Stewart deRamirez and with support from the Jump Applied Research in
Community Health through Engineering and Simulation partnership between OSF
HealthCare and the U. of I.
Bashir, Cunningham and King are affiliated with the Beckman
Institute for Advanced Science and Technology, the Carle Illinois College of
Medicine and the Holonyak Micro and Nanotechnology Lab at Illinois. Bashir and
Cunningham also are affiliated with the Cancer Center at Illinois and the Carl
R. Woese Institute for Genomic Biology.