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Silver nanoparticle labelling

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It is fine to promote your company's reagents. Just make sure they are relevant to CyTOF, and do so in moderation and style :-)
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afs1990

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Joined: Wed Jul 29, 2015 4:09 pm

Post Wed Jan 20, 2016 5:41 pm

Silver nanoparticle labelling

I was wondering if anyone has tried silver nanoparticle labeling, such as Cytodiagnostic's 10nm NHS-Activated Silver Nanoparticle Conjugation Kit?

The ionization energy of Ag is ~7.6 ev, which is lower than Au.

The signal would be split between 107Ag and 109Ag.

I'm just wondering if there is any reason not to use the silver nanoparticles, such as the memory effect seen with gold in ICP-MS. If you take a look at the Helios brochure, they tagged Au and Cd as example elements that channels that can be used in a 50 parameter panel, but don't mention anything about Ag.
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ParkerStensenson

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Posts: 1

Joined: Thu Apr 07, 2016 12:59 am

Post Thu Apr 07, 2016 9:24 pm

Re: Silver nanoparticle labelling

Realistically, this is probably too late of a reply, but after reading the wiki for the product https://www.everipedia.com/10nm-nhs-act ... ation-kit/ and the associated information I think our lab might order this possibly. I'll report back any interesting information soon. For reference I've used this before so http://www.cytodiagnostics.com/store/pc ... 3p2111.htm hopefully I can provide a good comparison post after the fact.
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mleipold

Guru

Posts: 2095

Joined: Fri Nov 01, 2013 5:30 pm

Location: Stanford HIMC, CA, USA

Post Fri Apr 08, 2016 3:30 pm

Re: Silver nanoparticle labelling

Hi all,

I think it's been mentioned before, but there's an upper limit to the size of a solid particle that can be ionized efficiently by the ICP-MS. At 10nm diameter, you should be ok, based on this email response from Fluidigm to my lab a couple years ago:

"
The question needs to be clarified in terms of the size of the particles and the number of copies per cell which they will be staining.

One issue (mentioned for gold) is that of the system “memory” – in this terms silver is somewhat better. Another issue is the exposure of the detector to high ion currents which can potentially be generated by a large agglomerates or highly stained cells. Thus, the number of atoms per particle and the number of particles per cell event need to be evaluated.

Then, I also had the following replies from Vladimir Baranov, another of our founders, on this topic:

1. Small addition to the last message. So far nobody was able to produce useful (stable, size uniform, and properly functionalized) silver nanoparticles. If something different appeared recently, we should learn about it.
2. It might be coincidence... but here it goes: ultrastable silver nanoparticles:http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12523.html

One thing we know for sure is that the bead or nanocrystal size must be <100nm (although, I’m sure your nanocrystals are well below 100 nm). It is difficult for the plasma to ionize particles larger than this size, and we don’t know the effect of unionized metal particles hitting the cones at the interface…this may damage them or build up on them (particularly over the long term).

All that said, the most relevant questions are 1) are your nanocrystals uniform in size?, 2) how many silver atoms/nanocrystal?, and 3) how many copies would be bound per cell? All of this will need to be evaluated to determine if the ion currents generated by these nanocrystals are within acceptable limits to avoid damaging the detector."


I assume you're planning to use them for low-expression markers, but just be careful with them. If I did the math right (and the entire 10nm of the particle is metallic silver), you'lre looking at 30,700 atoms/particle. In most cases, these particles are a smaller core with a functionalized corona: you might want to check with the manufacturer to confirm whether that's the case.

When we were looking at a different silver product (http://www.oceannanotech.com/product.php?cid=94&pid=292, AGA-07-0005) that had a smaller Ag diameter and therefore ~860 atoms/particle, we were told:

"Please note that the transmission factor of the CyTOF instrument allows measurement of one ion count per 1E4 atoms in plasma. Thus, if the low copies in questions are at 30 copies per cell, this will be just at a detection limit if staining is 1:1.

On the other hand, if there is non-specific binding or cross-reactivity, a 1E6 copies per cell will ring the signal beyond the dynamic range and may endanger the detector lifetime.
Perhaps if an experiment is planned in such a manner that the load on the detector is increased gradually (by monitoring all mass range in TOF window while increasing detector gain from a low value), such danger can be mitigated."


So, I would suggest you calculate the number of metal ions/particle, and make sure that you start out with a low titration. Hopefully Fluidigm will chime in to address your question.....


Mike
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afs1990

Participant

Posts: 12

Joined: Wed Jul 29, 2015 4:09 pm

Post Tue Sep 13, 2016 5:23 pm

Re: Silver nanoparticle labelling

Looks like the use of silver nanoparticles in CyTOF has been published earlier this year.

Here is a link if anyone is interested

viewtopic.php?f=10&t=510
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MCOlivier

Contributor

Posts: 32

Joined: Mon Oct 05, 2015 9:48 am

Location: European Genomic Institute for Diabetes, Universitity of Lille, Institut Pasteur de Lille, France

Post Wed Mar 27, 2019 9:57 am

Re: Silver nanoparticle labelling

Hi all,

Do anyone have more experience to share about direct labelling of antibodies with silver nanoparticles ?
This would greatly help ^^

Thank a lot and best day to all !

Olivier
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MCOlivier

Contributor

Posts: 32

Joined: Mon Oct 05, 2015 9:48 am

Location: European Genomic Institute for Diabetes, Universitity of Lille, Institut Pasteur de Lille, France

Post Mon Jul 15, 2019 2:39 pm

Re: Silver nanoparticle labelling

Dear all,

I've tested NHS Silver Nanoparticles Covalent Conjugation Kits (https://www.cd-bioparticles.com/p/Silve ... _3660.html) with no success... No labeling is seen with the conjugated AB (anti-CD8 from Biolegend 344727), even after washing of EDTA before starting the conjugation...
Even worse, all cells seem to be slightly positive for Silver (107 and 109).
Please, have a look to PDF enclosed (comparison with same AB labelled with 195Pt).

Suggestions ?

Regards

Olivier
(Desperate CyTOFboy)
Attachments
Silver CD8 test.pdf
(273.94 KiB) Downloaded 79 times

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