How often should Helios been run if not acquiring samples?

[lijiangwei]

Hi all,

I'm a new Helios operator and we don't have many users yet. Here are two questions to help our customers, all answers are welcome.

1. Assuming that the samples will be measured in three months, does the Helios need to be powered on during this period? Do I need to do tuning, bead clustering? How often should this be done? Once a day, once a week, or once a month? Why is this necessary? What are the benefits?

2, Is the completion of tuning and bead clustering enough to indicate that Helios is ready to acquiring samples? Do we need to acquire some cells to tell the user that Helios is ready? If so, how many cells are appropriate?

Your answer is an important reference for us to allocate our work time. Thanks in advance here.

Best,
Jiangwei

Jiangwei Li, PhD, SCYM (ASCP)
DART Cytometry & Cell Sorting Laboratory
NYU Grossman School of Medicine
522 1st Avenue, Smilow SR C34
New York, NY 10016
Tel: 212.263.5907

[mleipold]

Hi Jiangwei,

1. I would recommend that you use the instrument once per week or two, at least. It's our experience that the instruments are better-behaved if they're used rather than just sitting there for weeks/months on end. Even under COVID shutdowns, we still usually tried to get someone in to tune the instrument every week or two.

So, even if you're not running samples, I would still recommend igniting plasma and tuning the instrument. This will probably only take about an hour from ignition to shutdown, so it's not a huge amount of time.

2. In general, yes, completing Tuning is sufficient to log the instrument as ready to acquire samples.


Mike

[lijiangwei]

Hi Mike,

Thank you.

I can understand that flow cytometers need to be run regularly to decrease the chance of contamination. But here with mass cytometer, spending time to tune the machine without acquiring samples just increases the wear off of the machine. Tuning is largely dependent on alignment of injector, nebulizer and capillary, together with argon input. After we change or move injector, nebulizer or capillary, the tuning reports before don't make much sense. With flow cytometers, factors that have an impact on QC are almost same as before, cytometer setup and tracking makes sense, levey-jennings curve can show the stability of the machine, but here with mass cytometers, every time setup is more likely to start a new baseline of the machine.

To me, bead clustering is a good complementary of tuning. If the bead clustering is not good enough, the company should use standard cells samples to substitute beads. But it should not be necessary to run both.

These are my thoughts as a new operator, maybe they will change in the future.

Best,
Jiangwei