Costco, one of the largest wholesale retailers, begins selling coronavirus test kits online.

According to the Costco website, The PCR saliva kits can be used at home and don't need "painful nasal swabs."

The company wrote, "PCR tests are the gold standard testing method with the most accurate sensitivity and specificity currently on the market."

The at-home tests approved by the Food and Drug Administration for Emergency Use Authorization will help customers test coronavirus via saliva samples from home, office, or pharmacy self-administration.

According to the company's website, customers who take the test get their results within 24-72 hours from the time the lab receives the kit.

As per the Test maker P23, the tests are 98% sensitive — meaning the test will produce a genuinely positive response — and 99% specific, which is the probability the test, will have a real adverse reaction.

Costco has marked the item as FSA eligible, which means customers can now purchase the kit using a Flexible Spending Account for health care costs.

In July, Kroger Health, the supermarket brand's healthcare division, announced its COVID-19 Test Home Collection Kit would be available to front-line workers across its stores.

Kroger's kit included a nasal swab, transport vial, instruction sheet, prepaid shipping label, and packing materials for the sample's return shipment to the Gravity Diagnostics laboratory, located in Northern Kentucky.

The latest reports state that the United States has more than 8.4 million confirmed cases of coronavirus.