FAQ  •  Register  •  Login

Would you run this sample? (Pb contamination)

<<

jimbomahoney

Master

Posts: 73

Joined: Wed Feb 27, 2019 11:21 am

Post Fri Mar 20, 2020 9:48 am

Would you run this sample? (Pb contamination)

At what point do you decide a sample is too contaminated that it will excessively age the detector / compromise the data?

Other than trying to wash the sample again, are there any solutions?

e.g. would it be OK to run this without the Pb channels? I know the detector will still be hit, but how bad will that be in this case? (Possibly not that bad because it's "only" 100k DCs?)

Image
<<

jimbomahoney

Master

Posts: 73

Joined: Wed Feb 27, 2019 11:21 am

Post Fri Mar 20, 2020 12:51 pm

Re: Would you run this sample? (Pb contamination)

OK, washing removed the Pb and now I can run it.

Off-list reply was to NOT run the sample without washing it.

;)
<<

mleipold

Guru

Posts: 2156

Joined: Fri Nov 01, 2013 5:30 pm

Location: Stanford HIMC, CA, USA

Post Fri Mar 20, 2020 4:19 pm

Re: Would you run this sample? (Pb contamination)

Hi James,

How had that sample been prepared? In other words, how was it that horribly contaminated with lead with all the washing prior to you running an aliquot, but then a (few?) washes in your hands (with what?) got rid of it?

For the future: in general, no, I wouldn't run a sample that looks like that. The main issue is the detector, as you said. Even if you don't acquire those channels, the ions are still hitting the detector. And if you *do* collect those channels, your event rate will be nuts because of poor resolution.....in some cases with contamination, the number will go ridiculously high as everything gets counted as a cell, but your background streaks are bad enough that I'd bet you would have a low/no event rate where everything is basically seen as one giant cell.


Mike
<<

jimbomahoney

Master

Posts: 73

Joined: Wed Feb 27, 2019 11:21 am

Post Mon Mar 23, 2020 8:02 am

Re: Would you run this sample? (Pb contamination)

Hi Mike,

I don't know much about the sample, and I didn't wash it myself. I try and push back as much as possible to the users, leaving me to concentrate on maintaining, operating etc. the CyTOF (and the other instruments I look after / train users on).

All I know is that this is lung, which as I understand it, is one of the more "messy" tissues to prepare for things like flow.

Most of the samples are good, but occassionally, one comes along with Pb or Ba in it.

Washing (presumably with CAS) got rid of the Pb, but didn't work on the Ba in another sample.

The user is somewhat perplexed because they say that each sample is prepared in the same way. Plus they are usually preparing three tubes at a time, and only one of them may have contamination issues.

In addition, I always check the CAS, EQ and any other solutions I'm adding for acquisition, as I did have one batch of EQ beads that showed Pb contamination, but they'd been in a fridge for quite a while (almost empty bottle).
<<

MFoster

Participant

Posts: 2

Joined: Fri Aug 16, 2019 12:55 pm

Post Thu Mar 26, 2020 1:38 pm

Re: Would you run this sample? (Pb contamination)

Was serum used to block ? Goat serum can be high in Pb, so we avoid it and use mouse instead.

Return to CyTOF general discussion

Who is online

Users browsing this forum: No registered users and 4 guests

cron