FAQ  •  Register  •  Login

CAS Increasing background in long runs

Forum rules
Please be polite and civil. We know that troubleshooting is vexing...
<<

CRStevens

Master

Posts: 60

Joined: Thu Jul 17, 2014 5:07 pm

Post Fri Apr 15, 2022 7:18 pm

CAS Increasing background in long runs

Hi all,

We recently ran a larger than usual study and I have recently switched from the HT injector and water to the (not so new) WB injector and CAS. I ran for over 8 hours with multiple stops and starts to preserve files, but later realized my background on CD3 on 148Nd (specific to 148Nd and also 145Nd) was increasing drastically and converged over time with my signal. This left the last 3rd of my acquisition worthless.

I have done many runs in the past and hadn't seen this with water. I was curious if anyone else has a similar issue with the 140's range of metals with CAS?

Thanks,
Chad
<<

JamesW

Contributor

Posts: 37

Joined: Tue Nov 21, 2017 6:59 am

Post Sun Apr 17, 2022 11:51 pm

Re: CAS Increasing background in long runs

Dear Chad,

As far as I am aware this has been a common enough problem that Fluidigm have made the CAS plus buffer specifically to counter it, see attached PDF.
I have not used it myself as so far we have not encountered this problem on our Helios so can't say how well it works.

Best,
James
<<

CRStevens

Master

Posts: 60

Joined: Thu Jul 17, 2014 5:07 pm

Post Mon Apr 18, 2022 1:59 pm

Re: CAS Increasing background in long runs

Thank you James,

This is very helpful. I was not aware of this technical note and am still running my old trusty CyTOF2, so wasn't aware of the CAS+. I haven't had much issue with using the HT injector and Maxpar water in the past, but was trying to move along with the community. Unfortunately I had old and bad information apparently.

Do you get emails with these technical notes as like a community wide distribution? Hard to wade through the background and signal when it comes to emails and posts.

-Chad
<<

JamesW

Contributor

Posts: 37

Joined: Tue Nov 21, 2017 6:59 am

Post Tue Apr 19, 2022 12:01 am

Re: CAS Increasing background in long runs

Hi Chad,

In this case I just stumbled across the information by finding CAS plus in the fluidigm catalogue and directly enquiring with my local Fluidigm rep if it was worth using on a Helios. It certainly would be useful to directly receive that type of technical note as an email alert as I don't seem to be able to find the information on their website. Currently I rely on email alerts from CyTOForum to keep me up to date and had seen a related issue discussed before
viewtopic.php?f=4&t=1414

Anyway do let us know if CAS+ works for you in this case as there is not so much information on the subject. I am yet to see a clear explanation of why this occurs, we do up to 12hr runs with CAS without seeing this problem and I could not tell you why. Not sure if its a sample issue (fixation conditions?) or a machine issue.

Best,
James

Return to CyTOF troubleshooting

Who is online

Users browsing this forum: No registered users and 2 guests

cron