FAQ  •  Register  •  Login

Helios Detector Lifetime/Service Plan Value

<<

zebrafish

Participant

Posts: 7

Joined: Wed Nov 05, 2014 11:47 am

Post Fri Nov 30, 2018 7:19 pm

Re: Helios Detector Lifetime/Service Plan Value

Hi Mike,
My answers below:

1. If your Xe level is high enough that things are not passing tuning under the normal setup, then yes, your Xe level is still probably high enough that you're shortening the detector lifetime. For example, Xe131 (the normal Xe isotope in the tuning process) is 21.18% of natural Xe, while Xe128 is only 1.92% of natural abundance......more than a 10x difference.

What is your Xe128 signal intensity?

In the IMC mode, for a good argon tank, our Xe131 is < 2000. We currently are using Argon with Xe131 level at around 20,000. Fluidigm told us that as long as Xe131 is below 25,000, it won't have large impact on detector lifetime. Granted that this is not ideal, I don't think the high Xe level would explain why we burnt a brand new detector within a couple of month. We used Xe128 for tuning but are not recording its signal intensity directly.

2. I don't have experience with IMC, so I can't comment on how it tunes. However, I know in regular suspension Helios tuning with the Tuning Solution, the max Xe131 signal allowed before it would fail is 400,000 Dual. When Stanford and the SF Bay Area were having Xe contamination problems, this would often fail.

As I understand it, though, the issue isn't Xe131 itself, but the effects on other things in the Mass Calibration. Remember, the Mass Calibration step uses Cs133 (lower bound) and Ir193 (upper bound) from the Tuning Solution in order to calculate the TOF acquisition windows for all the other mass channels. It basically looks for the brightest signal in two certain TOF windows, and locks them as Cs133 (low) and Ir193 (high).

When Stanford had the problem, I was told that part of the issue with the high Xe levels is that there would be a chance that the Mass Calibration would lock onto a Xe isotope (probably Xe132 at 26.89%, but possibly Xe134 at 10.44%) *instead of* the correct Cs133. This would effectively miscalibrate the TOF acquisition windows for all the other masses. This could result in losing part of your signal, if the *actual* TOF arrival of the Tb159 (for example) ion peak was shifted up or down from what the Tuning had calculated based on Cs133/Ir193 Mass Calibration. This is similar to what happens over very long runtimes, as the TOF arrival of the ion peaks shift toward higher values (part of why you should retune your instrument every 6hr or so for very long runtimes, at least in suspension mode).

My understanding is that at least one lab at Stanford *did* experience miscalibration for one sample set. The way we and some other labs addressed it was going into the Tuning Manager and tightening the Cs133 TOF search window, so basically it couldn't search the areas that might be impacted by the Xe132 and Xe134 signals.


I don't know of a good way to retrospectively check whether a Mass was miscalibrated.....maybe looking at the Raw (unnormalized) EQ bead signal intensities and comparing them to historical (pre-Xe contamination) values?

I don't know how exactly changing the Xe isotope helps solving the tuning problem. But maybe the instrument can be more accurately identify a less abundant Xe isotope if the contamination level is high? How do you identify a mistuning? We looked at our data file after sample acquisition and the signal looks like what it is supposed to be. And for imaging data, there is a lot of variations between samples so it is hard to say whether we are losing sensitivity or not...

Mike
<<

DMcDonald

Contributor

Posts: 21

Joined: Thu Nov 26, 2015 10:14 am

Post Thu Apr 18, 2019 1:02 pm

Re: Helios Detector Lifetime/Service Plan Value

Hi All, I was hoping to reinvigorate this thread and see if anyone else is still having problems with abnormally short detector lifetimes on their Helios systems? We had 3.5 years out of our factory install detector but our replacement earlier this year didn't even last 2 months (linearly losing 100V a week). We've just had another replacement and following the trend over the first two weeks it looks like this one is going the same way as the second and it'll need replacing in another 5-6 weeks! We've got no obvious contamination in our TOF view and Xe131 duals during tuning are very low. We run in a split mode of IMC half the week and Helios the rest.

The DV for Hyperion mode is several hundred volts lower than Helios and I'm wondering if this bouncing around of the voltage between modes could be detrimental to it's lifetime? Any other thoughts or observations at other sights would be invaluable. Is anyone else having this issue?

Thanks in advance,
David
<<

Chowduck

Contributor

Posts: 29

Joined: Wed Nov 19, 2014 4:39 pm

Post Thu Apr 18, 2019 2:27 pm

Re: Helios Detector Lifetime/Service Plan Value

Hi David,

The detectors have a 2-year shelf life. Something to check would be if ETP Ion Detect can provide the date of manufacture for from the serial number of your detector (on the side of the blue packaging box).

-Greg Chang
<<

mleipold

Guru

Posts: 5796

Joined: Fri Nov 01, 2013 5:30 pm

Location: Stanford HIMC, CA, USA

Post Thu Apr 18, 2019 2:48 pm

Re: Helios Detector Lifetime/Service Plan Value

Hi all,

Greg: do you have a reference for the "2-year shelf life"? We have one kicking around that's approaching that, and it would be useful to know whether it's still good.

David: Unfortunately, different detectors have different lifetimes....from what I'm told, making them is a bit of an art on top of the science, and some are better than others. That said, 6-8 weeks is definitely unreasonable! Could you clarify when you received your Hyperion? In other words, when you said that you had 3.5yr out of the factory install detector, how much of that was Helios-only, and how much was Hyperion+Helios? With that first detector, did you notice a change in DV decrease when you started also using the Hyperion, relative to when you were Helios-only?

Also, what is your Ar dimer signal intensity (at least in Helios mode; no Hyperion experience, so I'm not sure if it's something you measure in Hyperion mode)? The reason I ask, if I recall from what my field engineer has said, there's a specific setting for Ar dimer suppression (DO2, maybe?). You might ask Fluidigm to check that; I could imagine that if it's "off" somehow, you could be blasting Ar dimer into the detector like crazy, which would presumably "age" it faster than normal.


Mike
<<

Chowduck

Contributor

Posts: 29

Joined: Wed Nov 19, 2014 4:39 pm

Post Thu Apr 18, 2019 2:59 pm

Re: Helios Detector Lifetime/Service Plan Value

Hi Mike,

https://www.etp-ms.com/faqs/frequently-asked-questions

"Q) What is the shelf life of an Electron Multiplier?
A) Contained in its original packaging, the shelf-life of an ETP multiplier is guaranteed for up to two years from the date of shipment."


I'm sure they will be good beyond 2 years, (like the Costco size bottle of acetaminophen I bought >5 years ago) but as we don't have a good handle on the cause of the issue with the replacements, it's something else to consider.

-Greg Chang
<<

eganio

Contributor

Posts: 21

Joined: Wed Nov 07, 2018 8:00 pm

Post Thu Apr 18, 2019 3:14 pm

Re: Helios Detector Lifetime/Service Plan Value

I'd be wary of the guarantee, since "shelf-life" could simply mean that it will actually function properly if it's installed after sitting on the shelf for 2 years. I don't think this necessarily translates as 2 years of life while in use.

Ours have lasted for varying amounts of time, depending on how many hours the instrument is used. They've lasted anywhere from 6 months to 2 years. We've found that the Helios will return to tuning at a lower DV if you let it "rest" for several days in between heavy periods of use. Doing a thorough clean also helps reduce tuned DV (clean spray chamber, injector, torch body, RFG coil, and both cones). Also make sure you are regularly cleaning out the metal capillary bolt that attaches to the PSI sample line and the nebulizer capillary line. It's an easy component to forget when cleaning the instrument, and is prone to clogging, since it has a very narrow aperture.
<<

GregBehbehani

Master

Posts: 85

Joined: Tue Apr 12, 2016 10:17 pm

Location: The Ohio State University, Columbus, Ohio

Post Thu Apr 18, 2019 3:29 pm

Re: Helios Detector Lifetime/Service Plan Value

Hi Everyone,

I would just like to add to the comments about detector lifespan. We have also noticed a large decrease in detector lifespan, going from about 2 years with our first detector to our current detector that we expect will only last a few months. While this has correlated with increased use, I don't have the sense that total run time correlates that well with the decline. One thing I have noticed (which I first observed back on 2012 on a CyTOF 1) is that the detectors seem to benefit from some "rest" periodically. Specifically, after a long run a repeat tuning will result in a significantly lower detector voltage (typically a decrease of 25 -75V), but that after a day or two without use, this will at least partially "recover" (regaining around half of the recent loss). I think the fact that our machine is now getting used every day and frequently on the weekends may be playing a bigger role in the how fast the detectors are wearing out.

Has anyone else noticed this "recovery" phenomenon? I wonder if having a day or two of rest makes a difference in the detector lifespan?

That all said, there have certainly been lots of detectors in the past that clearly had performance issues and abnormally short lifespans; I believe Fluidigm is aware of the problem and have been trying to investigate it for some time.

Hopefully it can be sorted out at some point.

best,

Greg
<<

mleipold

Guru

Posts: 5796

Joined: Fri Nov 01, 2013 5:30 pm

Location: Stanford HIMC, CA, USA

Post Thu Apr 18, 2019 3:43 pm

Re: Helios Detector Lifetime/Service Plan Value

Hi Greg and Ed,

In my experience, yes, you often gain back at least a little DV after a thorough cleaning of the instrument.

I will also say: I've noticed that when someone runs really bad-quality samples (really streaky from bad titer, debris, etc), it's not uncommon to lose 100V in a single day. However, over the next few days, as better-quality samples are run, the DV usually starts to recover a bit from day to day. For example, If someone runs bad-quality samples on Monday, Tuesday's tuning may be 100V lower than Monday's. If better samples are run in Tues and Wed, then by Thurs's tuning we usually have recovered at least 50V of those DV.

This is distinct from DV shifting during a long day's run. For example, let's say you tune to -1600V at the start of the day; DV might then shift to -1550V after ~7hr run of good-quality samples. However, when you shut down overnight and then retune the next morning, in my experience, the DV is usually closer to -1600V than -1550V.


Mike
<<

DMcDonald

Contributor

Posts: 21

Joined: Thu Nov 26, 2015 10:14 am

Post Thu Apr 25, 2019 10:41 am

Re: Helios Detector Lifetime/Service Plan Value

Hi All,

Thanks for your advice. ETP were helpful and quickly confirmed the manufacturing dates for me and quote "Contained in their original packaging, all ETP detectors have a guaranteed shelf life of up to two years from their date of shipment". At least one of the detectors was very fresh indeed so likely not the problem.

Mike: So the first factory install detector faired for 2.5 years using the helios +1 year using the Hyperion and Helios together pretty intensely. The second detector went in at the start of Feb and we're well into our third now. The only time not in use over the last year has been the early hours of some mornings and most Sundays. This last week the system had a two day break on Easter Sunday and Monday (Yes, I let the poor cytometer have a holiday and a chocolate egg). Despite the rest we've lost around 300V this week (I've been tracking it in Helios mode each Thursday) so something is going on! I'll be on to Fluidigm shortly.

The ArAr intensity doesn't appear to be horrendous, I'll take a closer look. I have no reference from other systems; would anyone be able to share what their signal intensities typically are in both Helios/Hyperion modes?

Thanks again for all of your help,

Best wishes,
David
<<

SabineB

Participant

Posts: 3

Joined: Mon Nov 25, 2013 2:20 pm

Post Thu Apr 25, 2019 3:50 pm

Re: Helios Detector Lifetime/Service Plan Value

Hi David,

I have it just open and can share the ArAr intensity on our Helios instrument: intensity is about 54 000 000 counts (dual 1 450 000 counts). Hope it helps!

Best Regards,

Sabine
PreviousNext

Return to CyTOF general discussion

Who is online

Users browsing this forum: No registered users and 9 guests

cron