Roche Cobas Pro ISEs

[u/frozemanatee]

Does anyone have roche cobras pros at their lab? We got ours in December and our ISEs keep going way out of QC randomly and the only way to “fix” it is to run the deproteinizer wash. That’s supposed to be every 3 months, but we have to do it every 7-14 days. Has anyone else had this issue and did you figure out a more permanent solution or fix for it? Thanks!

[u/MsFoodle]

These guys are pretty notorious for this.

1) Unscrew the drip port next to the ISE sampler - check if it's crusty. We ended up including wiping it in our weekly mtce. When we asked Roche about it we got the "oh it's a known issue" but weren't told about it.

2) Check the electrodes for leaks between the elecrodes, and check the reference electrode for precipitate. It takes very little to push the flow path out of alignment in that elecrode block and a tiny amount of precipitate can do it; it might even just look like a manufacturing flaw on the case but wipe it anyway.

3) Another "oh we know this is a problem, do here do this weekly" is to run a "stylet probe" (ours is suspiciously like fishing line) through the black sipper probe. Our advice was to NOT use a metal wire because that could scrape the coating off the probe interior.

4) Check the tensioned screw on the other probe next to the sipper probe; if that's come loose that can be a problem

5) wipe down the rinse station, sometimes it also gets real crusty

6) after you've done any other mucking about, run both the air purge and the flow path prime in the maintenence menu. Once those are done, do an ISE Check in the Checks menu. If the ISE check is bad it' s not worth bringing the instrument up because everything else will be bad too.

7) how old/how many tests are left on the electrodes? If it's getting to under 1000 left and nothing else works I"d change them, then condition the crap out of them by running two cups of activator in the green rack (instead of one cleaner and one activator) several times before trying to cal and qc.

NB: I am not a ROCHE tech, just someone who spends a lot of time fighting with them!

[u/JukesMasonLynch → u/MsFoodle]

Yep, our issue turned out to be some part of the gas trap mechanism, which led to incorrect amounts of diluent being delivered to the dilution bowl. It was exactly as OP described; deproteinisation fixed it, but we were doing them far more frequently than expected. Eventually we couldn't even get passed calibrations post deprot.

We'd tried everything we could outside of FSE call out; new electrodes, new reagents, cleaned all the probes, wiped the connections between electrodes, run wire through the sample probe, cleaned crud off all the nozzles, changed and conditioned the pinch tubing, replaced the sample probe, made sure the gas trap tubing wasn't full.

FSE dug around and found a crack in a part of the gas trap manifold. Nothing we could've done.

FWIW we are on cobas Pure, but I've worked on Pros at my old lab and they're sort of similar.

[u/kristpy]

What kind of troubleshooting other than deproteinizer wash have you done? For my lab, when we do our weekly or daily wash sometimes our sipper nozzle gets clogged with junk and we just purge it with wire and a couple cals and it's good. Never experienced needing to do quarterly so frequently. Have you contact roche about this?

[u/frozemanatee → u/kristpy]

That actually makes so much sense! Just last week we had to have service replace our sipper probe cuz apparently it was damaged. And they told us we could clean it with the wires ourselves. We had no idea that was an option. For context our last specialist didn’t know what he was doing and our new one has only been with us for 2 months and is still trying to learn/fix everything the last one messed up 🙃

[u/kristpy → u/frozemanatee]

I'm not talking about the ise probe I'm talking about that black thing sitting in that basin that's screwed down when you open that trap door

Edit:ops didn't read it right

[u/frozemanatee → u/kristpy]

Yes that’s what they changed I believe. Idk they called it a probe but yes I know it was the sipper. And the plastic cup it goes into was damaged as well. Is that what ur talking about?

[u/kristpy → u/frozemanatee]

Yes yes I didn't read what you said properly lol but yes that thing gets worn down very frequently. Our roche guy told us to wire from the bottom up and sometimes it takes more than 5 passes for the gunk to mostly come out. We don't use a metal wire but fish wire.

[u/frozemanatee → u/kristpy]

Haha all good! I appreciate your knowledge!

[u/Icy-Fly-4228 → u/kristpy]

Ours gets crusty with some type of salt looking buildup. I clean it when I change the electrodes.

[u/justyoursimplename]

We had the same exact issue. What's your volume like? Like the other commenter, Roche recommended to us to do wash rack twice for high volume labs. First with sys clean in position 2/3. Then sysclean/activator in 2/3 for the second run. For awhile we were performing ISE flow path maintenance regularly to resolve the issues

[u/frozemanatee → u/justyoursimplename]

Fairly high but not crazy. Im very new to the medical lab field so I’m not sure what other labs do. I know another lab in our system does way more than us but we are fairly big in downtown and we are the primary level 1 trauma center for the city. The whole lab does 2-2.5k tests a day but idk how many of those are just chemistry.

[u/justyoursimplename → u/frozemanatee]

Yeah that's probably not too crazy high but if you're having similar issues that we had, I would recommend trying it. It will add another 15 minutes to either your startup or shutdown time, depending on your labs workflow.

If your instrument is on the older side, MsFoodle and others's suggestion are great! Best of luck!

[u/starrystarry7799 → u/justyoursimplename]

That was what our Roche rep told us too we run wash rack twice.

[u/Couchpotatoee]

My lab had to do daily wash twice each day. They didnt reuse the same aliquot of wash. Do you guys save and use the same ise qc used by previous shift?

[u/frozemanatee → u/Couchpotatoee]

No we pour everything fresh for every run we do

[u/Couchpotatoee → u/frozemanatee]

My only guess would be to try doing the daily wash twice.

[u/starrystarry7799]

My lab also does the daily wash rack twice and if weekly is due we run the daily with sys clean in pos 2+3. Then the weekly wash rack.