What is the liquid used in LFT's? Can I use saline?

[ItsAllAboutTheLighting]

I had a box of LFT's, all the little pots disappeared.

This happened two more times before I figured out the cat was taking them. No idea where he's put them.

It means I have a lot of sticks and little test boats but no fluid.

Seems such a waste, could I either use a different kind of fluid (saline?!) or order just the extraction fluid?

My dog ate a whole bunch so I had to look up what was in them.

It's not saline. There are also, according to the product safety sheet, "No harmful effects expected in amounts likely to be ingested by accident."

I have no idea if saline would work or not - sorry. But at least I can reassure you you don't need to worry about your cat.

My understanding is that the buffer solution IS saline

@x2boys

I was idally pondering the other day if you could mix and match the tests and the fluids any one know ? Ds2 was sent home last week from school last week with some LFT,s in a totally different box from either the old type of LFT,s and the Flowflex ones ,produced in China I think ,I'm always mislaying the separate parts so it was a thought that crossed my mind .

Yeah, I don't think it was a good idea to design the little boxes to cram everything in, so that after the first time you take one test, you cannot fit everything back in properly so inevitably end up losing a part...

It's a buffer solution which means that it keeps the pH neutral. This is why the kids were able to get positive tests using orange juice - the acid turns the test positive, using the buffer solution stops this unless the antigens being tested for are present.
TLDR: saline is not a buffer on its own so can't be used.

@DaveDave

I think saline is fine - ours was missing so we use contact lens cleaner. Worked ok ( well picked up my positive confirmed by PCR). Unless coincidence!

That was exactly what I was planning on using.

To be fair, if you mean contact lens solution rather than just saline, I think that is buffered too. Goodness knows what else it might have in it to interfere with the test though!

@Cookerhood

To be fair, if you mean contact lens solution rather than just saline, I think that is buffered too. Goodness knows what else it might have in it to interfere with the test though!

Thats interesting, what does buffering mean exactly?

If you’re sensible enough to be testing regularly, why on early do think it’s wise to be doing so with any old random liquid you can get your hands on.

For gods sake just take better care of things - I’m sure if we had to pay £25 for two tests like they do in the US you wouldn’t have let your cat ruin 14 of them.

www.lumiradx.com/assets/pdfs/compliance-documents/extraction-buffer-safety-data-sheet.pdf

A myriad of things-though prob about 99% saline. However you can only use the buffer provided for the test strip it comes with

www.mediskincare.co.uk/about-us/articles-news-case-studies/2020/06/07/faq-covid-tests/

Contact lens solution wouldn't be the worst choice I can think of — the LFT buffer is going to be pretty close to neutral I would think, which would be a similar pH to contact lens solution.

I wouldn't recommend it though, you need the tests to be accurate!

Pretty sure it’s purified water. It’s DEFINITELY not something that grows virus

A buffer is something that keeps it the same pH. (It either absorbs or releases H+ ions which is what affects how acidic or alkali something is)

@AlandAnna

Pretty sure it’s purified water. It’s DEFINITELY not something that grows virus

It's absolutely not purified water. Not sure if you mean the test buffer solution or contact lens solution, but neither are purified water. Maybe read the thread, it's not that long.

@ItsAllAboutTheLighting a buffer is a solution which stays at the same acidity no matter what you add to it. If you drop something too acidic on the test strip you can fake a false positive, apparently. The buffering solution prevents that from happening even if your nose-slime is super acidic for any reason.

No idea but I never use all the solution, so I would be trying to use only half of your remaining pods and putting what remains into an airtight container for the next test.

@Clarabellawilliamson

A buffer is something that keeps it the same pH. (It either absorbs or releases H+ ions which is what affects how acidic or alkali something is)

Thanks!

@LivingInaBuildingSite

One of my cats has taken a particular liking to the swabs in their packets.

Misses point of thread 😂

Yeah one mine goes mad for test kits! She tries to get into the box and steal the swabs.

@Clarabellawilliamson

A buffer is something that keeps it the same pH. (It either absorbs or releases H+ ions which is what affects how acidic or alkali something is)

Huh, thanks! We have buffer fluid at work for some tests we use and I've always wondered what it was, especially after seeing it in the Covid tests as well.

This might have solved the mystery of what happened to our buffer solution.

I’ll bet the bastard boycat swiped it off the unit and batted it under something immovable.

@TheUndoingProject

If you’re sensible enough to be testing regularly, why on early do think it’s wise to be doing so with any old random liquid you can get your hands on.

For gods sake just take better care of things - I’m sure if we had to pay £25 for two tests like they do in the US you wouldn’t have let your cat ruin 14 of them.

Because I couldn't get anymore LFTs for love nor money in any of the chemists. My solution was missing (or perhaps hidden in the booklet I now realise). I had booked a PCR so thought I would try contact lens solution out of scientific enquiry (boredom). DP did it and was negative. Mine was positive... who knows!

From the UK Animal Poison Centre, for those worried about pets.

"As with everything- as items enter our houses, our pets have the potential to get their paws on them shortly after!
We have recently received a few enquiries about pets chewing and ingesting the solution of the COVID-19 rapid test. This is a buffering agent or extraction solution. There is usually only a few millilitres available and- as far as we are aware- they containing no hazardous ingredients. Some testing kits contain a isothiazolinone preservative but the concentration is very low and so not an issue.
We would not expect any toxicological hazard from these tests."

I was trying to work this out too. We had some old kits where the tubes were more or less empty so couldn't use them, and other ones where I squeezed the tube and fired it anywhere but where it was supposed to go! Then we've got some new kits where the tubes are missing - either not there or maybe I accidentally threw them away with the box.

Anyway, I thought if it was buffer I could probably get some at work, but I can't find which type of buffer by googling. I'm pretty sure that the antigens are contained within the strip itself.

Thats interesting, what does buffering mean exactly?

It's how you know you're getting ripped off by BT Broadband.

I'm fairly sure the extraction buffer will be a dilute detergent solution, in order to lyse the cells you've scraped from your nose/throat so that the viral proteins within can interact with the lateral flow test strip. In theory, you could make this with washing up liquid. You'd need to make sure the detergent solution is dilute enough not to denature the proteins though.

www.gavi.org/vaccineswork/what-lateral-flow-testing-and-how-could-it-be-deployed-against-coronavirus

I have loads of solution as NHS staff used to get a big box of 25 tests which had a dropper bottle of solution as some ways of testing used more than others and I only used a tiny bit!
We should have an exchange system