Is this positive lateral flow?

[Samcj02]

Hi,

I’ve just taken this lateral flow and this was the result, is this positive or inconclusive?
I did repeat the test and had a negative, I’ve also ordered a PCR.

Yep both positive.

I can't believe people cannot see the lines. Their screens must be awful.

I can see a faint line on both of them

@vegas888 there is clearly a second line on both. Turn your screen brightness up or get glasses.

I would say it is positive. I had the exact same with my son. However three PCR tests following where all negative. 🤷🏼‍♀️

Definitely a line

This is positive, unfortunately. My DD had a couple of faint positive LFTs, and a couple of darker ones, and she then had a positive PCR.
The latest LFT pack I’ve received give an example of a negative result and 2 examples of a positive result, and one of the positives have a faint ‘T’ line.
It’s scary how easy it is to miss the second line; I always imagined it would be much more obvious.

I'm normally rubbish at spotting faint lines on pregnancy tests but even I can see the faint lines in both of the OP's LFTs

I had a faint line like that and several PCRs were negative.
Let us know the outcome OP good luck x

Thanks everyone, we’ve had a small outbreak at work hence the LFT, I’ve felt fine but all of a sudden cough, headache and achy, I’ll update with my PCR results.

Good luck OP and get well soon

@KineticSand

Good luck OP and get well soon

Thank you xx

There are lines on both.

All the best OP. I hope you feel better soon.

Both are positive. I've no idea how some posters are saying they can't see a line!

Whether you're positive or not, I hope you feel better soon 💐

Thank you everyone! I think this is the problem some people dismiss faint lines on these tests.

Hands up that I'm only educated in Molecular Biology to bachelors level and I did terribly on my immunology units so take the below with a pinch of salt however...

LFT work by basically proteins binding to proteins. So if you have the antigen (think of it as a key) in your system at a high enough level then when you apply it to the LFT unit it spreads up the paper and binds to the corresponding antibody protein (lock) which then changes the colour.

You can have covid but just have low levels of the antigen in your system at that point in time so you don't happen to 'catch' any when you swab (I also think you're highly unlikely to be contagious when LFT are returning negatives as there clearly isn't much covid stuff there in your nose/throat so I don't think you'd be transmitting much but as I've said, huggggeeee pinch of salt as I'm not well educated on this subject, plus you're always going to have faulty tests). A positive is generally always a positive though as the test has matched that lock and key together and that is a pretty specific match. The BBC have a good article on how the tests work and also talks about how they were being spoofed with soft drinks due to the acidity, rather than unspecific binding.

www.bbc.com/future/article/20210705-how-children-are-spoofing-covid-19-tests-with-soft-drinks

PCR stands for Polymerase Chain Reaction which is just the process used for replicating the nucleic acids, in this case the viral DNA. You can 'catch' the smallest bit of viral DNA with the swab for this one which is then multiplied hundreds of times when the test is processed before they then check it for covid.

That is why it's quite common to have a negative LFT and then a positive PCR. If you do another LFT a few days later I think you're likely to return a clearer positve.

Oops sorry viral RNA, there would be trouble if it was DNA.

I think that's a line
Get a pcr test my son had two with faint lines and then he got a positive covid result from pcr
Mine then no line at all with lateral flow but still had a positive pcr test

@tnetenba thank you for taking the time to explain that!

@tnetenba

Hands up that I'm only educated in Molecular Biology to bachelors level and I did terribly on my immunology units so take the below with a pinch of salt however...

LFT work by basically proteins binding to proteins. So if you have the antigen (think of it as a key) in your system at a high enough level then when you apply it to the LFT unit it spreads up the paper and binds to the corresponding antibody protein (lock) which then changes the colour.

You can have covid but just have low levels of the antigen in your system at that point in time so you don't happen to 'catch' any when you swab (I also think you're highly unlikely to be contagious when LFT are returning negatives as there clearly isn't much covid stuff there in your nose/throat so I don't think you'd be transmitting much but as I've said, huggggeeee pinch of salt as I'm not well educated on this subject, plus you're always going to have faulty tests). A positive is generally always a positive though as the test has matched that lock and key together and that is a pretty specific match. The BBC have a good article on how the tests work and also talks about how they were being spoofed with soft drinks due to the acidity, rather than unspecific binding.

www.bbc.com/future/article/20210705-how-children-are-spoofing-covid-19-tests-with-soft-drinks

PCR stands for Polymerase Chain Reaction which is just the process used for replicating the nucleic acids, in this case the viral DNA. You can 'catch' the smallest bit of viral DNA with the swab for this one which is then multiplied hundreds of times when the test is processed before they then check it for covid.

That is why it's quite common to have a negative LFT and then a positive PCR. If you do another LFT a few days later I think you're likely to return a clearer positve.

Thank you! That’s really interesting!

@AvaCallanach

Yep both positive.

I can't believe people cannot see the lines. Their screens must be awful.

This. Sorry OP but look like 2 clear positives to me.

You can have covid but just have low levels of the antigen in your system at that point in time so you don't happen to 'catch' any when you swab (I also think you're highly unlikely to be contagious when LFT are returning negatives as there clearly isn't much covid stuff there in your nose/throat so I don't think you'd be transmitting much but as I've said, huggggeeee pinch of salt as I'm not well educated on this subject, plus you're always going to have faulty tests). A positive is generally always a positive though as the test has matched that lock and key together and that is a pretty specific match.

Thank you. After our experience I definitely think this is the case. Dd caught Covid on Sunday. The year group was told to isolate on Monday. She got a sore throat on Wednesday, but kept getting negative LFTs on Wednesday and Thursday. On Friday she had a positive LFT and straight away isolated to her room completely. None of the rest of the family caught it 😅

@tnetenba thanks for a great explanation, and sorry to jump on the thread with a question but what are your thoughts on why someone might get positive LFTs, but negative PCRs? Anecdotally this seems to be on the increase, and I'm still trying to understand my own recent illness.

Went to a
Drive through this morning as showing lots of symptoms so fully expecting my pcr to be positive!
I’ll update with result x