As Scotland faces a new Covid wave, we’re all being advised to lateral flow test (LFD) again, if possible. LFDs are a quick, easy and reliable way to find out if we could have the virus.
Testing enabled us to continue socialising safely through the first Omicron wave and will be crucial in reducing the size of the next wave.
When testing positive, two lines appear on the lateral flow test.
But what should you do if a faint line appears? Or if a line shows after the 15 or 30 minute mark? Does this mean you’re positive? Or are you safe to carry on as if you’re negative?
We’re answering all your questions on lateral flow tests.
Lateral flows and the different result times
Free Covid testing has now ended for most people in Scotland. However, you can buy tests from pharmacies.
According to the Scottish Government, if you have coronavirus symptoms, you should stay at home and avoid contact with others until you feel better.
Depending on the type of lateral flow test kit you have, you’ll have to wait between 15 and 30 minutes to read your test result.
If you have the blue and white NHS box, you should wait 30 minutes to read your result. You should not read the result after 30 minutes as this makes it void.
If your tests are the ACON Flowflex kind, you should wait 15 minutes before you read your result. The result can be read any time between 15-30 minutes. You should not read the result after 30 minutes.
For Orient Gene tests, you can read the result after 15 minutes. Instructions say not to leave the test to develop for longer than 20 minutes, as this will make the result void.
If a line appears next to the T before the time limit, you should assume you are positive, no matter how faint it is.
You should hold your test up to light at the 15 or 30 minute mark so you can be sure to see any faint lines that might have appeared during this time.
What if a faint line appears after 30 minutes?
But, what happens if you take a test, return a negative result, and when you look at it later on, there’s a faint, clear line next to the T?
Does this mean the result is void, or should you assume you have Covid?
While this is rare, it has happened. However, it doesn’t necessarily mean you have Covid.
If a faint line is slightly coloured (like in the picture below) and appears before the time limit, you should assume you are positive and isolate wherever possible.
We’ve had a good run but it’s finally caught us. Positive LF for the 7 y/o this morning. pic.twitter.com/9wQ2erMMLS
— Kirsty Strickland (@KirstyStricklan) January 24, 2022
If the line is clear and appears after the time limit, this is likely a false positive or void result.
It’s not entirely certain why this can occur, but it could be down to contamination from food or drink.
If you’re concerned, you can complete another lateral flow test and check the new result within the allocated time frame.
Scottish Government Covid advice
According to the Scottish Government, lateral flow test results should only be read and reported at 30 minutes.
If a positive signal appears after 30 minutes, it should not be reported as positive.
Waiting longer than 30 minutes can create false positives and the C line must be coloured to have a valid test result.
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