'Lab on a chip': Faster COVID-19 antibody test

A new portable "lab on a chip," developed by the U-M scientists and demonstrated with help of the CDI, can identify the presence of COVID-19 antibodies in blood donors with greater speed and efficiency than the current standard "enzyme-linked immunosorbent assay" or ELISA technology.

Together, the CDI and U-M researchers have shown the device can identify COVID-19 antibodies in human blood in 15 minutes -- much shorter than the few days the process normally takes. The test can also be done with smaller amounts of blood.

The work could have particular value for the validation of convalescent plasma as a treatment for COVID-19. A paper on the findings is published in Biosensors and Bioelectronics.

"Convalescent plasma is a treatment that can be very effective -- but for it to have the best chance to work, it needs to have rigorous standards, which include assessing the presence of high-titer neutralizing antibodies," said David Perlin, Ph.D., chief scientific officer and senior vice president of the Hackensack Meridian Center for Discovery and Innovation, and one of the new study's authors. "This paper shows how the antibody thresholds can mean a better potential COVID-19 treatment -- and also better outcomes."

"This research shows what an important role microfluidics can play in both saving lives and costs during the COVID-19 pandemic," said Xudong (Sherman) Fan, U-M biomedical engineering professor and co-founder of Optofluidic Bioassay.

The U-M device detects the presence and amount of neutralizing immunoglobulin -- antibodies created by the immune system within seven to 10 days of a COVID-19 infection. Only donors with high levels are likely to provide samples that could be effective in treatment, such as convalescent plasma therapy.

The treatment involves taking plasma -- the liquid portion of the blood that contains antibodies -- from survivors and infusing it into sick patients to boost their immune response.

Thousands of patients nationally have been administered convalescent plasma through a program overseen by the Mayo Clinic. Hackensack University Medical Center also has its own clinical trial underway involving high-titer (levels) of antibodies.

The lab-on-a-chip approach developed by U-M analyzes on-site and requires just a finger prick's worth of blood -- 8 microliters. The traditional ELISA methods require 100 microliters to do its work. The U-M system is contained in a device the size of a portable 3D printer.