A group of pupils at Blanchelande College were placed in isolation after Covid-19 tests they used as part of an A-level biology lesson gave a positive result.
Two students and a teacher also had tests carried out at the hospital, which turned out to be negative.
The students were learning about a new covid test being used in parts of the UK and Europe to give them a greater understanding of immunology.
The tests are different to those used by Guernsey's Public Health Services. We're told they have a 20% higher chance of giving a false positive result than those used by our health authorities.
Following confusion over the results, the school isolated the group and contacted Public Health for guidance.
The school has written to parents assuring them there is no reason for any concern. It's also confirmed that it is reviewing its procedures.
"While this exercise provided our students with a real-world experience of the latest technology available to screen populations for Covid-19, we will certainly be reviewing our procedures, and we are of course relieved that everyone is in good health and grateful to the staff at Public Health for their support this afternoon." - Robert O'Brien, Principal.

Guernsey dance school upset by temporary theatre closure
Guernsey's business leaders come out against a plan to pause GST
Plans to improve the gene pool of the Royal Golden Guernsey Goat
Fog causes flight chaos at Guernsey Airport
Channel Islanders asked to report injured or dead seabirds
More than 200 emergency callouts for overflowing cesspits in Guernsey
Guernsey Library to host Costume Creation event ahead of World Book Day
Domino's Pizza to open in Guernsey