estimating costs

[cellsort]

Hi All,

I've been viewing this forum for some time but still have some basic costs questions as a Helios is being considered for my core.
I have estimates of service contracts, gas and supplies etc, but am wondering what is the experience of those who may not heavily use their systems.
Is at all feasable to have someone part time who knows the instrument well but helps out with traditional flow? Should the system remain on to maintain vacuum even if it is idle for weeks? If not in regular use should you run EQ beads 1X per week in any case?
On a slightly different topic, is there any resolution to the debate over titrating vs not fluidigm reagents? ie is 25 test really 25 test?

THX from a potential newbie

[dtelad11]

Full disclosure, I have never been involved with managing a CyTOF firsthand, but I have been working with labs and cores since the instrument was first released (I'm a computational biologist).

From my point of view, if your system is going to remain idle *for weeks*, then getting your own machine would be a waste of time and money. The CyTOF is expensive, the reagents are expensive (and you need a lot of them), operating it is difficult, and there is a non-trivial amount of training required. In my opinion, the most successful CyTOF providers out there are those whose machine is working full-time.

I think that the best solution for you would be to collaborate with an organization that already has an instrument. They can ship you the reagents, you can prepare and stain the samples on your end, and ship them for acquisition. I have spoken to at least one core that offers this service and have experience with similar arrangements. Furthermore, this would allow you to conduct a trial, of sorts. You can run a couple of hundred samples, and then decide whether to purchase your own instrument.

If you're interested, I would love to chat more and I could also connect you to several potential collaborators (both in Canada and in the US). Email me at el.ad.david.amir@gmail.com.

[mleipold]

Hi Derek,

The Helios instruments are meant to be left powered on to maintain vacuum in the ion optics (quadrupole, TOF, etc) sections. It will take a minimum of a few hours to get the vacuum to the correct levels after shutting it down; overnight is often better to make a really good vacuum. Also, depending on how long it's been turned off (and exposed to atmosphere), part of that time will be getting moisture out of the system. The HIMC only turns off their instruments as needed for service calls, otherwise we leave them powered under vacuum even over holiday breaks.

The instruments are generally happier if they see a certain amount of use.....I'd say 2-3hr per week, if possible. So, if you turn on, warm up, Tune, clean, then run EQ beads and then clean again, you'll probably be pushing the 1.5-2hr mark, which is probably sufficient.

I personally find that it's worth testing the Fluidigm antibodies: most of them will be 1 uL=1 test, but some will be slightly over- or under-titered at that point. I think everything I've worked with has been in the 0.5-1.25uL per test range. I will say: we've seen some differences in titer between experiment types. For example, live-cell assays (live surface phenotyping, live cell surface staining during intracellular cytokine staining) sometimes have different titers than fixed-and-perm'd assays like phosphoflow, especially for things like CD45 and CD45RA. So, it's probably worth an experiment to test that out. For the Fluidigm conjugates, my experience is that they remain at the found titer (ie, no need to retiter between tubes or even lots). But I haven't tested that exhaustively.


If you're not using the Helios very often, then argon supply is something you'll want to consider. Liquid argon low-pressure dewars are cheaper on an hourly basis, but will exhaust and vent themselves just sitting in the corner. Conversely, compressed gas argon cylinders are more expensive on an hourly basis (one 2500psi cylinder is typically 6hr of runtime for *one* machine*), but you can leave them in the corner for months or years without losing any argon. Our typical advice to new operators is that somewhere around the 20hr (3cyl), 2-3 days/week mark on a regular basis is where you usually want to switch to liquid argon.


Mike

[cellsort]

Thank you all who've given your values advice and insights, both directly and via the Forum!
All fantastic information.

This forum is invaluable to current users as well as potential users of the Cytof technology, and a great educator for us flow people trying to grasp all the issues and abilities!

Derek