Indium chemistry

[mleipold]

Hi Naeem,

Generally speaking, the metal salts are stable in slightly acidic conditions indefinitely. I'm still using some master stocks I made 5-6 years ago, with no change in signal intensity. It's important to keep them acidic, though: at neutrality and basic conditions, you can get some precipitates (oxides and hydroxides, from what I understand). In a lot of cases, re-acidifying can re-dissolve the precipitate, but it's easier if you don't let it happen in the first place.

Honestly, I use standard clear (non-colored) translucent polypropylene lab Eppendorf 1.5mL microcentrifuge tubes (substocks) and 15mL conicals (master stock), and haven't seen any issue. In a previous lab, my advisor who did a lot of bioinorganic chemistry suggested not using the colored tubes, as the colors sometimes come from metals (or at least have metal contaminants associated with them). But I haven't tested that myself.


Mike

[GregBehbehani]

I can agree with everything Mike said. We do it exactly the same way with good results.

Good luck,

Greg

[nkhanbham]

Thanks Mike and Greg.
So if one was to dissolve the 1M stock in L buffer (say 1ml worth, and dilute to 50mM with more L) would that also work? I am assuming L buffer is also slightly acidic.
Naeem

[GregBehbehani]

Yes, that's how we do it. (Just be sure to keep your 1M stock seperate, it would probably be an issue if someone used if for labeling.)

best,

Greg

[mleipold]

Hi Naeem,

Formally, we don't know the composition of L buffer (DVS/Fluidigm has been maddeningly unwilling to tell people, at least on the record).

However, the link below (from a much older discussion) suggests that L buffer is probably Ammonium acetate, pH 6.0.

viewtopic.php?f=7&t=454&p=1447&hilit=L+buffer+TBS#p1447


And yes, I second Greg's comment: if you're going to have a concentrated master stock, make sure it's kept well-separated from the diluted working stock: different box on a different shelf, etc.


Mike

[nkhanbham]

Thanks guys. Forgot to ask earlier - do you store the 1M stock at 4C or room temperature?

[mleipold]

In my experience, it doesn't matter if you store at RT or 4C.

The main issue would be evaporation of the water component of your solution, thereby making your concentration higher and potentially affecting things. But if your tube is tightly closed, then centrifuging it to get all the water droplets down back into the main liquid solution will fix that.

[Chowduck]

Hello,

We are considering buying isotopically enriched 113In metal from Trace and would like to know if anyone has experience with this and if so, has used it in conjunction with naturally abundant indium (~4% 113In & ~96% 115In). The spill with naturally abundant indium into 113 seems negligible and I suspect we can get away with it using an appropriate panel design but anyone else's experience with this would be appreciated.

Thank you,
-Greg Chang

[GregBehbehani]

I use purified 113 all the time, but only with purified 115. You will still have some spillover from 113 into 115 as Trace will sell you 113 with about 4-5% 115 contamination. So I typically use CD3 on 113 and CD45 on 115 since the T cells tend to have high CD45 anyway, the spillover doesn't change anything.

I imagine you could just use purified 113 with natural In, but then you'd have spillovers in both directions, which I just prefer to avoid when possible.

Good luck,

Greg

[Jahangir]

Hi guys,

Many thanks for all the information, learning loads!

I have a slightly different question. I was recently told by a Fluidigm Tech that I am not able to use the Indium metals with the Palladium barcodes supplied by Fluidigm, but they didn't tell me why that was. Does anyone know why the two can't be used in the same experiment?

Many thanks,

Jahangir