Gordon Stein, CFO of CleanTech Lithium, explains why CTL acquired the 23 Laguna Verde licenses. Watch the video here.
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We regularly use lateral flow type devices for drug detection in the construction industry. Basically there is a kind of swab on a stick made of dense like gauze material (about the size of an uncompressed disposable earplug) which you stick in your mouth and chew until it goes soft. You then take the other component of the kit which is kind of like the outside body of a syringe, insert the swab and compress until your saliva starts to drip out of the nozzle. You then just place a few drops on the receptor plate of the cassette and just wait a few minutes.
No idea, stanman, but I thought it might be interesting to see how saliva was collected in the studies that have showed it to be a good alternative to the nasopharyngeal swabs.
One study comparing saliva with nasopharyngeal swabs:
https://www.medrxiv.org/content/10.1101/2020.04.16.20067835v1
“Saliva samples were self-collected by the patient. Upon waking, patients were asked to avoid food, water and brushing of teeth until the sample was collected. Patients were asked to repeatedly spit into a sterile urine cup until roughly a third full of liquid (excluding bubbles), before securely closing it. All samples were stored at room temperature and transported to the research lab at the Yale School of Public Health within 5 hours of sample collection.”
Another:
https://www.medrxiv.org/content/10.1101/2020.05.13.20100206v2
“Saliva samples were self-collected by the patients except one patient, in whom saliva was collected by swab due to inability of self-collection, and spit into a sterile PP Screw cup 50 (ASIAKIZAI Co., Tokyo, Japan). 200 microL Saliva was added to 600 microL PBS, mixed vigorously, then centrifuged at 20,000 Xg for 5minutes at 4oC, and 140 µl of the supernatant was used as a sample.“
I’m sure others exist, but these were the first studies I came across - and I think they’ve been linked recently here. Both have spitting in common, rather than swabbing in the mouth. The first method sounds a bit extreme for a mass use test! Second one, like the Sona test, adds another liquid. I suppose there could be some collection receptacle shipped with the Avacta test? Sounds like a swab won’t be necessary. Hopefully it can take just saliva without adding an extra liquid, but you can imagine if so there may be some variability in performance based on the variable viscosity of saliva dependent on hydration...
Personally I’d prefer as little extra equipment shipped with it as necessary while giving a high performance test. More user friendly, and less materials reducing cost and environmental waste. No doubt the experts are working on these things right now, anyway. They clearly have a lot on their plates!
Thank you Canute40 for your reply. As it happens, I am familiar with LFD's and the use of buffer solutions to prepare samples before using the device. I was just interested to learn about how saliva is used - directly, or with a buffer, or what?
I have no experience with the use of saliva as a medium, but it seems at first sight that the characteristics of saliva may vary quite markedly from person-to-person, and certainly more so than urine (eg preg tests) or with serum/plasma/whole blood (many LFTs).
Of course, Cytiva may have already done the necessary work in this respect already. We can safely leave it to them I trust. I just hope that whatever is required does not add to the complexity of test use, and detract in any way from its end-user appeal or from easy passage through the FDA or CE-marking approval.
It'll be easy to use for Avacta shareholders, we've been constantly drooling at the prospect of the rising share price
There are many types of these devices available commercially.
Reference is made to "the technique and collection device(s) used to obtain the clinical sample" in the "Antigen Template for Manufacturers" document which has to completed and included with submissions to the FDA. Any submission will have to include details of sample collection.
Does anybody know how saliva will get on to the relevant part of the Avacta/Cytiva lateral flow device?
Does the user simply dribble a bit of spit on it, aiming very carefully?
Or get some saliva into a glass, and "pour" a drop on to the slide?
Or use a dedicated device? If that, would the device be supplied with the slide?
Or if the slide is sterlised, and seal-wrapped, could the user open it and say put the sample end of the slide under the tongue for say 20 seconds?
I don't know the answer - but I am curious to find out what the real options are?
Ease of use is obviously important commercially speaking, and is of considerable relevance to regulatory authorities for POC end-user tests.