They're not even testing for antibodies. AND it's COV-2 (SARS). According to the official CDC website.

• CDC is working to develop a new laboratory test to assist with efforts to determine how much of the U.S. population has been exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19.

How does one virus "cause" another virus??

• The serology test will look for the presence of antibodies, which are specific proteins made in response to infections. Antibodies can be found in the blood and in other tissues of those who are tested after infection.

Nobody has been able to identify (isolate) antibodies specific to COVID-19 yet. This makes all current testing inconclusive.

• https://www.cdc.gov/coronavirus/2019-ncov/about/testing.html

And, The World Health Organization,

• https://www.who.int/docs/default-source/coronaviruse/protocol-v2-1.pdf

They only claim to be able to identify genetic markers for COV-2 (SARS).