Manx Care says their PCR testing is of the 'highest clinical standards.'
It follows reports of some people testing negative for the virus at the Grandstand - despite having previously tested positive with Lateral Flow Tests.
The health body says since March 2020, the Covid testing lab has performed approximately 140,000 tests, which are close to 100% accurate.
On the Island, Manx Care says lateral flow tests correctly identify a positive case about 90% of the time, however there are rare occasions when an LFD shows positive and a PCR shows negative.
The Island follows recommendations from the UK Government Health Security Agency and remains in line with international standards.
Manx Care also thanks everyone involved in the Island's testing, and says its proud of the services they provide.
Difficult to compare Island's Hospice funding with UK, says minister
Mountain Road to close because of gales
New amber warning issued for tonight's storm
Police appeal over theft of building materials
One of capital's oldest buildings may become housing
New NHS safety rule to be brought in on Island
Two city streets to shut for over six months
Revamp of airport terminal planned, says DOI