Lab Guy
The term "test kit" has been misused to the point that people are confused.
Historically a test kit refers to a collection of devices, reagents, calibrated pipettes and cartridges needed to complete the test. Those are all put together in a self contained package on a per unit test basis that manufacturers sell.
In the beginning of COVID the only test available was a complicated nucleic acid test that only a few places were capable of doing. In order to do the test one needed a swab collected and put into a fluid media called viral transport media. That media was sent to labs doing the testing. As time went on and more testing became more prevalent there became a shortage of such media. The media was synonymous with the "test kit" and it was reported that we were short of test kits. We then became short on the swabs needed for the testing. After those shortages the labs reported shortages on the actual reagents needed to do the testing.
One needs to keep in mind on how the shortages came about and how it was difficult to overcome. Laboratories are highly regulated and must adhere to strict testing methods that are submitted to the FDA for approval. Every swab, device and reagent used in the test must be identified and used. One can not use substitutes. We can not just change swabs or reagents without FDA approval. We would be out of compliance if we did.
Once more hospital labs started doing the testing like Abbott quick test the instrument used to perform the testing was made available to many labs but the actual testing cartridge used for each test was limited to 50 per day. The actual test kit is a cartridge that one places inside the instrument that contains the reagents for testing.
In the future a test kit will be available for testing blood for antibodies similar to doing a pregnancy test. The test kit will be comprised of a collection device, small pipette, and a self contained cartridge that will show lines of color when positive.