The photo on the left is a low magnification electron micrograph of a monkey kidney cell after infection with the Omicron variant. It shows cell damage with swollen vesicles containing small black viral particles.

The photo on the right zooms in further. From the high magnification version of the same infected cell, one can see aggregates of viral particles with corona-shaped spikes on their surface.

Earlier in November, researchers at the Department of Microbiology at HKU succeeded in isolating the Omicron variant from clinical specimens.

The isolated variant will enable the development and production of vaccines against Omicron, which has been designated as a "variant of concern" by the World Health Organization.

WHO said the Omicron variant possesses multiple spike protein gene mutations, and the spike protein gene targets may not be detected if the testing institution uses a particular and single polymerase chain reaction-based nucleic acid (PCR) testing kit that gives quick results.

A private Covid-19 testing laboratory has been removed from the Hong Kong Department of Health's list of recognized testing institutions because the testing kits it used may not be able to identify the Omicron mutant strain.

The department said that the testing kits used by the Medtimes Molecular Laboratory in Kwai Chung can only detect two targets at the coronavirus's spike protein gene, and it may not detect the Omicron variant, which has multiple spike protein gene mutations.