Hello, I’ve had a persistent problem with small particles of unknown material being introduced into vials through the pump system, which interferes with OD readings and potentially contaminates our cultures. These particles show up even when only purified water is being pumped through the lines, and no amount of flushing with any common solvents (bleach, ethanol, water) seems to remove them. After having eliminated all other possible sources of contamination, my conclusion is that either the tubing itself or the luer lock components at the ends of the tubing must be the source of these particles. Are there any suggestions about how best to mitigate this? Thanks, Eli
Hi Eli,
Mind sharing pictures of your fluidic lines and if possible the particles? It’s hard to diagnose without that.
Hi Nate, thanks for responding. It is a bit difficult to get pictures since we have our setup inside an anaerobic chamber, but I have done my best to show the full setup. I also have a picture of the particles in a vial of LB media that was pumped directly from a clean container.
I also found that there are no particles present when the luer lock component is removed and media is dispensed from the tubing itself, so I suspect that this part is the culprit. Do you have any suggestions on how to clean the luer lock components? Are they autoclave safe?
Thanks, Eli
Those are some small particles! I wouldn’t expect them to interfere with OD readings unless there were a whole lot of them.
Considering the luer locks are all nylon (hard inert plastic), we’ve never had an issue with particulates coming off of them. They should be fine to autoclave, though this would only sterlize them and not remove particulates.
While unlikely, it’s possible that the batch of luer locks you got has these particulates. Perhaps try unplugging them and swirling them around in bleach to dislodge? Also pumping for an extended amount of time should eventually fix your problem right?
Best of luck!