On Friday, the FDA published a list of molecular tests for COVID-19 that may be affected by mutations in the omicron variant of concern.

• The agency's list focuses on coronavirus tests impacted by S-gene dropout, an occurrence that is most commonly associated with Thermo Fisher Scientific Inc's TMO TaqPath test kits. 
• When TaqPath is used on a variant with a deletion in the spike gene, such as alpha and omicron, it only detects two of the three target genes.
• Since the S-gene is detectable in the dominant delta variant, the FDA asks laboratories with "access to quick turnaround whole-genome sequencing services" to consider sequencing samples affected by dropout. 
• FDA has identified 26 molecular tests affected by S-gene dropout. The best-known tests on the list are three versions of TaqPath from Thermo Fisher.
• The other 23 tests listed by the FDA include a product from Verily Life Sciences, backed by Alphabet Inc (Google) (NASDAQ: GOOG.
• Like TaqPath, the Verily product tests for three parts of the SARS-CoV-2 genome, meaning it can deliver a positive result by identifying the ORF1ab region and nucleocapsid gene even if there is a deletion in the S-gene. 
• Price Action: TMO shares are up 1.09% at $629.01 during the market session on the last check Tuesday.