Gov. JB Pritzker announced Sunday that the state conducted 19,417 tests in a single day, marking Illinois' highest daily testing total so far.
The testing milestone comes as the state's number of coronavirus cases climbed by 2,994 to a total of 61,499. Illinois' COVID-19 death toll has reached 2,619, state health officials reported Sunday.
"We're doing a lot more testing than most places in the country," Gov. Pritzker said.
The previous high was reported on April 24, with labs processing 16,124 tests in a single day.
Pritzker has said increasing testing capacity is crucial in the fight against COVID-19, setting a goal of processing 10,000 tests a day early last month. It took weeks to reach that milestone.
In north suburban Waukegan, the Illinois Department of Public Health opened a new drive-thru testing site.
Lake County has the third highest number of confirmed cases of COVID-19 in the state, behind Chicago and Cook County.
The Illinois National Guard is running the free testing site at a vehicle emissions testing facility.
"Five-hundred tests a day is what we are limited to," said Illinois National Guard member A.J. Ruggieri. "That is due to the amount of tests that the labs can process. That may vary. It may go up. It may go down with time, but right now, it is at 500."
Pritzker wants to ramp up the state's testing capacity even more.
He said he's working to get access to more equipment and supplies.
"We need swabs. We don't have enough swabs. We are getting more from the White House, actually. But you also need viral transport medium and you need the reagents that are necessary to run the test," the governor said.
Pritzker has faced mounting frustrations on the first days of the state's relaxed stay-at-home order.
Protesters have been rallying against the modified order that took effect May 1. A demonstration was held in far north suburban Fox Lake Saturday, a day after hundreds gathered outside Chicago's Thompson Center.
RAW VIDEO: Stay-at-home order protest in downtown Chicago
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On Friday, Pritzker said he would consider lifting the order before May 30th for certain regions of the state, if they see two weeks of case declines.
"I want as much as everybody else does for everybody to get back to work, and for us to move toward normalcy," Pritzker said. "But I also want to say that I'm not going to do it until we know people are safe, and it isn't going to be because some protester has a sign that says, you know, 'Liberate Illinois.'"
The governor said any region that he would consider reopening before May 30th would have to have enough hospital and ventilator capacity to handle any sudden surge in cases.