New LFT not really working

[StrongLegs]

Hi,

Is anybody else finding that these new lateral flow tests are not really working that well?

Half the time when I our family do them, the liquid doesn't ever make it to the control line, and then if it does we always get a big smudge at the T line, which makes it really hard to tell if it is possive or not.

With the old tests it was always either definitely negative or clearly positive.

@Chemenger

Other than the foil being virtually impossible to get off I haven’t had a problem. It is 4 drops and 15 minutes, as PPs have said. The instructions are very clear about squeezing out the swab, otherwise there wouldn’t be enough liquid. I would imagine adding extra liquid invalidates the result.

I always squeeze the swab thoroughly and 4 drops is optimistic.

I'll read the instructions. Thanks.

My new ones are really poor quality - foil on the tube is glued on so hard you have to cut it off and then the tube is compromised.

Leftbutcameback yes I had that with the first few flowflex ones. The more recent boxes seems to have that problem solved and the foil comes off okay now.

This is how much liquid I have left after doing 4 drops, seems strange that people don’t have enough to do the drops.

You're just doing it wrong op - you need to read the booklet and follow the instructions the first few times you take the test.
After that you'll remember how to do it.

Your tests look positive to me - although you've flooded the kit.
Can you get a PCR done to make sure?

I'm going to bail out of this thread and try again using the instructions now. It doesn't make sense to me, because even with all the drops, the water doesn't usually reach the control line, but I will have another go.

Thanks for the advice.

@stronglegs this is mine - who knows if positive or negative with colour dye run!

I find there’s too much liquid, flooding it is what causes those smudges. I use two drops and wait for it to reach control line, never found not enough. The old tests frequently didn’t have enough liquid.

You need to really squeeze the swab to get the liquid out, and make sure you've closed the lid firmly. If it's not fully closed I've found the liquid can go down between the lid and the tube.

Ours have always worked fine but the silver tops that you peel off break on I’d say 1 out of every 3! And I’ve had some with hardly any liquid and one had a big split down it and I didn’t notice until I was mixing the sample and ended up with fluid and snot all over my hands 🤢 not even my snot.

I agree there's too much liquid! The dye runs like that when you've put too much in. Just do 3 drops, should have some left over. Here's ours from positive results. Was very easy to tell with just 3 drops.

Is the solution at room temp. Probably not the cause but they must not be carried out in cold conditions.

twitter.com/michaelmina_lab/status/1467719470651219969?s=10

The main issue I have is getting the foil off … not in all boxes but probably half we’ve had

I had an issue with the swab coming off in the tube when u have to squeeze it.

Thankfully there seems to be enough liquid unlike the last few of the old sort where I wondered if they'd forgotten to put any in there was that little

I have had floflex and orient gene nose only ones.
Both have different instructions so you always need to read them - one is between 15 and 30 minutes and the other is 15-20 minutes. They both use 4 drops though unlike my nose and throat ones that only use 2 drops (and take 30 minutes)

@Earwigworries

The main issue I have is getting the foil off … not in all boxes but probably half we’ve had

Absolutely! DH keeps those plier/wire cutters handy to peel it off which works half the time but the other times I either get the solution over me or the little silver tab rips off 🙄

I use flow flex, no issues just follow the instructions and no issues putting 4 drops on the bit

Those tests look positive to me

I’ve found the flow flex ones with the foil top much better than the old ones where I struggled to have enough liquid for 2 proper drops. Get 4 easily from these. No issues getting a clear control line showing up, they don’t look anything like the picture.

No issues whatsoever, and plenty of liquid. But as others say make sure you squeeze the swab on the side.

There is plenty of buffer in the flow flex ones (Innova one however never had enough in the last few batches we had). Are you pinching the swab at the bottom as you rotate it and then squeezing the liquid back off before taking it out? I could probably do 3 tests with amount of buffer I have in mine! I would a) go and get a PCR as those look positive b) count the drops from the vial carefully because they look like they have far too much solution on them and c) blow your nose before you take the test, too much snot can make the solution run slowly!

I’ve used a few different and never had an issue with not enough liquid. Are you squeezing the swab as you remove it from the vial?

I'll read the instructions. Thanks.

I’m not sure why people arent doing this before attempting the tests.

If I use one liquid none comes out and the test is wasted. My one doesn't have foil its the twisted top one.