QuidelOrtho Corporation is an American manufacturer of diagnostic healthcare products that are sold worldwide.

[8] In 2000, Quidel acquired Litmus Concepts, Inc., a privately held in vitro diagnostic company.

[13] In May 2020, Quidel’s Sofia 2 SARS Antigen FIA has become the first COVID-19 rapid antigen test to be granted Emergency Use Authorization (EUA) by the FDA,[4][14] approved by FDA director in charge of authorizing test EUAs, Tim Stenzel.

[15] In December 2021, Quidel announced it would acquire Ortho Clinical Diagnostics Holdings for $6 billion in cash and stock, increasing the range of COVID-19 antigen and antibody tests the business is able to offer.

[17] The following is an illustration of the company's major mergers and acquisitions and historical predecessors: Since its merger, Quidel has expanded its product base through internal development and acquisition with a focus on increasing its research and development efforts to accelerate the rate of new product introductions.