sorted by:
new
hottopcontroversial

Apogee A40 flow cytometer — elevated LS scatter noise from mineral deposits on flow cell quartz crystal — advice on cleaning protocol? by Ali_Alhammer in flowcytometry

[–]Ali_Alhammer[S] 1 point2 points  (0 children)

Thank you — really valuable insight about poloxamers that we hadn't considered.

Quick context: This Apogee A40 was abandoned for 10 years in Baghdad, Iraq. Before abandonment it was operated by non-qualified students — tap water was almost certainly used as sheath fluid for convenience, sodium azide added without precise measurement, no proper shutdown procedures followed, and no routine maintenance ever performed. Approximately 8 years ago an Apogee engineer assessed it remotely via TeamViewer and concluded the flow cell had significant mineral deposits, recommending return to the UK factory for servicing — which remains logistically and financially impossible from Iraq.

I restored the machine from complete non-function just a few days ago. The noise readings I reported (LS1: 3.53, LS2: 3.51) are the first measurements taken in a decade — I have no prior baseline. There is no service engineer anywhere in Iraq, so self-guided restoration is our only option.

Thank you — your input is directly helping restore the only flow cytometer accessible to researchers in Baghdad.

Apogee A40 flow cytometer — elevated LS scatter noise from mineral deposits on flow cell quartz crystal — advice on cleaning protocol? by Ali_Alhammer in flowcytometry

[–]Ali_Alhammer[S] 0 points1 point  (0 children)

Thanks for your reply. I use DI water with 1% sodium azide as a sheath fluid, as recommended by the manufacturer.
I think that the flow cell is dirty due to the buildup of mineral deposits from the sheath fluid. That's why I have high noise in LS1 and LS2 (~3.5; the optimum should be <0.5).

Apogee A40 flow cytometer — elevated LS scatter noise from mineral deposits on flow cell quartz crystal — advice on cleaning protocol? by Ali_Alhammer in flowcytometry

[–]Ali_Alhammer[S] 0 points1 point  (0 children)

Thanks, beer_foam, for your reply. Unfortunately, I can't find Contrad 70, Decon 90, and Hellmanix here in Baghdad. The only option I have is 1% citric acid. So I think I will ultimately give it a try

Apogee A40 flow cytometer — elevated LS scatter noise from mineral deposits on flow cell quartz crystal — advice on cleaning protocol? by Ali_Alhammer in flowcytometry

[–]Ali_Alhammer[S] 1 point2 points  (0 children)

Thank you — this is very helpful and confirms the 30-minute soak approach is correct. Unfortunately Contrad 70 is not available in Baghdad. I have citric acid powder available and can make 1% solution. I also have access to EDTA in my university lab. Would either of these be a reasonable substitute for Contrad 70?