COVID-19 is an RNA virus, and contains no DNA. Both DNA and RNA viruses exist, so the author’s confusion is understandable.
Both DNA and RNA are nucleic acids, which can code for proteins. RNA, which is less stable than DNA, also has catalytic properties.
Human cells contain DNA, mostly in the nucleus, that is translated into RNA, and that RNA is then transcribed as a template for manufacturing proteins in the cytoplasm of the cell, in cellular subunits called ribosomes that are themselves composed of both RNA and proteins.
An RNA virus such as the one that causes COVID-19 inserts its own RNA into the cell and essentially hijacks cellular mechanisms to produce proteins and RNAs of its own which then self assemble copies of the virus, including its lipid and protein capsule. Finally, it breaches the cell membrane and infects other cells.
It is unclear to me from the article whether the Abbot test recognizes the virus’s RNA or one of its proteins, since either approach is possible.
It seems likely from the author’s description that it this test uses an RNA microarray in which the analogous DNA sequences are used as part of the microarray. Thus, DNA is used as part of the microarray technology, but is not part of the virus itself.