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Ah - i think that's Prof Milners group. They are doing a fair bit with affimers and keep watching. Good to see that its been tried before
RD, I am sorry I didn't post the ref. I found it here:
Production of a novel Affimer based biosensor for the detection of porcine reproductive and respiratory syndrome virus nucleocapsid protein.
Jackson, Zoe (2017) Production of a novel Affimer based biosensor for the detection of porcine reproductive and respiratory syndrome virus nucleocapsid protein. PhD thesis, University of Leeds.
St
Let's hope so Trek, and thank you to your contributions as well ??.
Hi Mr ST. Where different you find the affimer and membrane stuff - mportantly, the Affimers were indeed shown to maintain their binding ability to the target sample upon rehydration.
The packing (and alignment) is an important aspect for LoD. Looks reassuring.
The timing of the tweet is interesting. The content that they tweeted is nothing new. It’s been on the website for ages. Why cut and paste it into a tweet just now is the question.
An RNS tomorrow to say they have selected a compatible membrane for affimer LFT from their existing product range would indeed blow the doors off the SP!
So perhaps when/if that RNS lands Cytiva have just lined up a little marketing pr to coincide. All guess work.
Trek
...
Their small size lends itself to compact packing onto the membrane and along with their beta-barrel structured nature we can infer that unfolding is not likely to occur if stored correctly. Antibody based tests have been shown to be stable for 2 years post manufacture if stored according to the manufacturer’s instructions (Life Assay Diagnostics. 2010). Affimers have been shown to be stable in solution up to approximately 100 °C (Tiede et al., 2014), suggesting they would be suitable for use in both temperate and tropical temperatures, vital for the incorporation into a diagnostic against PRRSV which is a global disease".
Cheers
ST
Good afternoon all,
On LFA point, thank you Doggy100 for the Cytiva link, I found the aspects mentioned on the manufacturer's explanation on the strip selection very useful, as you can see the extracts below. I then remembered I had read a clinical study on affimers and I have extracted some interesting references regarding LFA, which you can also see below.
From Cytiva:
"A successful lateral flow immunoassay depends on a series of reactions. When selecting materials for immunoassay development, membrane properties and reagent properties must be considered together, as their interactions determine the outcome of test development.
When selecting a membrane, you must consider how the various materials and properties will interact with your reagents and sample to meet your test goals for sensitivity, specificity and test duration. Factors that will affect the interactions between your sample and the membrane include:
Viscosity of the sample liquid
Compatibility of the test reagents with the membrane surfactant
Kinetic properties of the binding reagents
Binding kinetics of capture reagents and membrane compatibility:
"Whether a specific capture reagent, e.g. a monoclonal antibody, provides the sensitivity and specificity required in a lateral flow rapid test depends not only on the membrane used, and the surfactant incorporated in the membrane; it also depends on the kinetic properties of the capture reagents".
From the academic article:
"The novel nature of Affimer reagents meant that it was unknown how they would perform in many aspects of the LFD development process. As well as being immobilised, they also were required to migrate along a membrane whilst maintaining their ability to recognise their target protein. A key feature of the device is the immobilisation and dehydration of the Affimer reagents at the test line site. It was not known if this would result in the proteins becoming denatured or if they would be able to maintain functionality once rehydrated.
Importantly, the Affimers were indeed shown to maintain their binding ability to the target sample upon rehydration, suggesting that they retained their structural integrity during the dehydration and rehydration processes. Due to time constraints of the study, the Affimers dehydrated on the membranes were not stored for longer than 24 hours before rehydration and so it is not possible to comment on the long term storage stability of these reagents. It is likely that the Affimers will be stable once immobilised onto the nitrocellulose membrane for a number of weeks if not months if they are kept at an ambient temperature and not exposed to moisture.
Their small size lends itself to compact packing onto the membrane and along with their beta-barrel st
Are gene drive the ones with the aminoglycoside test for newborns?
Get on.....
I think activa and genedrive will fly out the traps and I’m hoping hemo will but not to excited really
I don’t think you will be able to get tmoz first thing
IMO
Thanks for posting Doggy. Explains why its a bit quiet from Cytiva - at least they have lots of potential combinations and the expertise to develop others. Wonder if they want to supply the Avacta membrane choice to other companies and that's the point of the tweet. Bugger I've just started guessing at stuff - its contagious.
Nice, good to see both parties know how to develop the best possible test.
Thanks for sharing - " Learn more from Dr. Klaus Hochleitner."
Interesting timing of tweet ( same Klaus Hochleitner from RNS quote below )
"Klaus Hochleitner, Global Lead, Technology Product Specialist at Cytiva, commented:
"I am delighted and impressed with the rapid progress made by our partners at Avacta and look forward to receiving Affimer reagents to implement in a lateral flow test on our platform as soon as possible."
No mention of Avacta
Seems to discuss and explain the different membranes available for tests with the pros and cons