Donald “DJ” Hall and his colleagues in the College of Medicine were responsible for processing tens of thousands of tests and variant sequences for Drexel and the city. Their work made it possible for students to return to campus, helped the region monitor new variants and transformed several academic careers.
Hall had just completed his doctorate in chemical biology and medicinal chemistry and was about to begin postdoc research when the lockdown halted everything.
He suddenly found himself instead building an emergency COVID lab with a team led by his PhD adviser-turned-boss, Garth D. Ehrlich, professor of microbiology and immunology and professor of otolaryngology in the College of Medicine. They took over a shuttered clinical diagnostics laboratory inside an empty Center City building. In record time, they assembled machinery, operations, protocols, systems, accreditations, personnel and supplies.
To pull it off, Hall put in 16-hour workdays and “basically lived in the building,” he remembers with a rueful grin. At first, he and other technicians processed vials by hand, up to 5,000 tests each week — enough that the University could safely reopen in January 2021. By the time the Omicron variant emerged, the lab was running up to 1,200 tests a day.
“I’ve never heard of this happening anywhere else before,” Hall reflects. “We went from nothing, to running samples for surveillance in just a few weeks, to reinstating the lab’s clinical license and running diagnostics and becoming accredited in just over a year.”
The Sequences of COVID Sequencing
The Integra Assist Plus is a liquid handler that transfers samples from a patient to a dilution plate to remove salts in the test solution, prior to mixing it with a batch of reagents for chemical analysis.
The Mantis liquid handler contains a master mix of reagents that amplify the COVID RNA in the sample to detectable levels.
The Kingfisher Flex is an automated DNA and RNA extraction system that contains magnetic beads to collect and isolate the RNA from the sample mix. This machine can prepare as many samples in one hour as it used to take the technicians a day and a half to do.
The Pac Bio Sequel IIe: once isolated and washed, RNA samples are put inside this machine, which analyzes and sequences their genomes.
At peak, the lab was processing up to 10% of all polymerase chain reaction (PCR) tests in Philadelphia. In addition to providing peace of mind to in-person classes, the lab also helped with sequencing samples collected by the Children’s Hospital of Philadelphia and by the Philadelphia Department of Public Health.
“We contributed significantly to the amount of COVID sequences in Pennsylvania, when we were producing 5–10% of the sequences for the whole state,” Hall recalls.
Altogether, the lab completed about 130,000 PCR tests between fall 2020 and fall 2022, when Drexel began winding down COVID testing. Once Philadelphia eventually opened its own sequencing lab in summer 2022, city personnel sought out Hall for advice. One vendor even called to thank Hall for the referrals.
Professor Cheryl Hanau, the Richard Shuman, MD, Chair of the Department of Pathology & Laboratory Medicine, was essential to the lab securing accreditation, but she gives Hall the lion’s share of the credit.
“Dr. Hall’s intellect, adaptability, curiosity and determination were what made this lab a success,” she says. “I don’t see how it could have happened without him.”
Now that the crisis has passed, Hall’s career is on a new path. A grateful College of Medicine awarded him an assistant professorship in 2022, and now he will (finally) resume his own research, mentoring his own students this time.
He’s experimenting with a novel material that could lead to self-sterilizing respirators and face masks, and he recently published his first paper as a corresponding author. He’s also studying, with Ehrlich and his chemistry faculty adviser Frank Ji, ways to inhibit an enzyme that causes bacteria to become metabolically resistant to antibiotics. Ehrlich calls it one of the most important things he’s ever worked on.
As for the COVID lab, he’s staying on as operations director, but with a new mission. He and his team are retooling it into the newly named Drexel Medicine Diagnostics Laboratory. Now, it will be a full-service, revenue-generating diagnostic lab that can run tests for infectious diseases, genomics and toxicology. This time, he was given a leisurely 12 months to equip it.
“It’s definitely been a journey,” Hall reflects. “I went from being a chemistry undergraduate student focusing on bioanalytical chemistry, to a doctoral student focusing on medicinal chemistry, and then put on a microbiology hat as a postdoc, started a diagnostic lab, and then was offered an assistant professorship. I took the opportunities that were presented in front of me; I followed what I found interesting.”