CyTOForum

Hi All,

We are running frozen multiple myeloma samples in Helios. The technician is running the samples and she is complaining about our samples causing a block in nebuliser when running each sample. Before, giving the samples I thoroughly wash and filter the cells but still cloging problem. How to tackle the problem ? The machine was started after a long shutdown.



Sincerely
Komal

Hi Komal,

It's possible that the instrument itself needs a complete clean: running lots of Wash, 3% nitric (and/or Tuning). Also, dismantling and cleaning/flushing all the user-accessible parts including all tubing and connections in the PSI (since you didn't state otherwise). The nebulizer capillary might need to be replaced. The ground nut might need to be removed and sonicated.

It's also possible that the nebulizer needs to be cleaned (or a new nebulizer used), as there may be dust, threads or hairs, or other "junk" clogging it. You should be able to see that under a microscope.

Once all that's done, making sure that the Tuning solution looks ok (dark, solid lines), and undiluted EQ beads (from the bottom of a well-shaken bottle) are running 80-100 events/sec (~10K events in 2 minutes), then your system should be fun.

After that, the only real explanation is the quality of your samples.


Mike

Totally agree with Mike here. We've had several experiences where certain poor quality samples from collaborators seem to be more "sticky" than the ones we prepare ourselves, and cause numerous clogs during acquisition. For whole blood, it seems that over-fixed / improperly stored samples tend to be the culprit. Also, in our experience, some nebulizers seem slightly more susceptible to clogging, perhaps due to slight variability in capillary shape/size. After a thorough clean, perhaps try a different nebulizer and see if the problem recurs. If sample quality is the real issue, this is unlikely to make any difference.

-Ed