This is the page about the kits/methods to detect SARS-Cov-2.
To detect this virus, in the market there are two different strategies: 1) direct detection by using its RNA and protein 2) indirect detection by targetting IgM or IgG against the virus 
The figure below illustrates when these two different strategies can be used.
As seen above each scenario has a different scientific/diagnostic meaning
To see the big picture we need to have different commercial kits/methods.
1. Direct Detection Methods (DDM)
The direct detection methods aim to detect the active infection or SARS-CoV-2 itself. We can classify them as Nucleic Acid (NA) Based Methods (NBM) and Protein-Based Methods (PBM).
1.1. Nucleic Acid-Based Methods
1.1.1. PCR Related Methods
Nowadays, the most famous NBMs are RT-PCR derivatives which are RT-qPCR and RT-ddPCRs.
- CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel was published.
- CDS recently declared the primer and probe panel (pdf) to detect Covid-19. Nucleocapsid (n gene) of the virus is targetted. The panel targets three N regions: N1, N2, and N3. N1 and N2 are specific to Covid-19 whereas N3 is a universal probe/primer set for all SARS viruses. This panel was modified and optimized by companies and they produced new products such as:
- IDT Covid-19: it uses a plasmid as a positive control
- Biodesix ddPCR kit (RNA based positive control), and Bio-Rad Covid-19 multiplex ddPCR assay. Bio-Rad sells both qPCR and ddPCR assays (RNA based standards used).
- CDS recently declared the primer and probe panel (pdf) to detect Covid-19. Nucleocapsid (n gene) of the virus is targetted. The panel targets three N regions: N1, N2, and N3. N1 and N2 are specific to Covid-19 whereas N3 is a universal probe/primer set for all SARS viruses. This panel was modified and optimized by companies and they produced new products such as:
1.1.2. Other Methods
Recently, Abbott launched a novel Covid-19 test kits. The kits use isothermal amplification to detect RdRp gene of SARS CoV-2 virus. Although the company does not give detailed information about the technique, I think they use LAMP technology.
1.2. Antigen Detection (Protein-Based Methods):
Although there are a few RNA strands in each virus, the number of protein molecules is enormous. In addition, RNA isolation is not necessary, which is highly important for labs which has weak or limited supply chain to reach RNA isolation kits.
