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Galileo & ECHO reagent controls


RR1

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It would be good to know the frequency and types of reagent controls users run on the Galileo and ECHO, as I want to optimise my running of this equipment

We currently perform following :

1. Galileo (4 cells screen) : Internal ABO Cor QC in the morning

2. Weak antibodies : anti-D, anti-c, anti-K, anti-Fya- morning and afternoon.

3. ECHO : Grouping whole blood controls once a day

4 Weak antibodies : anti-D, anti-c, anti-K, anti-Fya- morning and afternoon.

Thanks

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I'm curious, why are you running the "Weak antibodies : anti-D, anti-c, anti-K, anti-Fya- morning and afternoon."?

Is this an UK thing? I'm fairly confindent in saying that in the US most of us have never QC'd panels. I'm sure some have but not many.

Before I left the wonderful world of Trnsfusion Medicine our process was the same as clmergen's.

:crazy:

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Echo - Our process is the same as clmergen's.

Also, I have the same questions as John....... Do you ever find a variation in the Antibody Identification results from shift to shift or day to day? If you have gotten different results, please discuss your findings (so others who have those instruments might benefit.)

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Thanks everyone, at the moment I am trying to optimise and simplify the way we are handling our controls. As most of you know we have had many problems with antibody detection on our analysers over last 16mths. Most of this has been resolved by changing cameras, washers, etc.... ...but the most significant change was introducing an improved wash assay which removes plasma prior to the wash cycle.

The weak antibodies we use are to ensure there are positive and negative reactions observed on each of the Capture-R screening cells ( 4 cell screen on galileo, 3 cells on ECHO), not for the ID panels.

The Immucor pos and neg controls run with each batch of samples tested, don't control each of the screening cells.

We run our weak abs twice a day to ensure the analysers are performing optimally - and yes- these have been known to fail, and the answer from Immucor is usually- it's not the correct control for this technique. Looking back- this was an indication of poor plate washing.

As for the ABO Rh controls, the on-board QC used on Galileo does not reflect a control of the actual reagents being used. I will soon be changing this and dropping CorQC, to make it sensible, using the new WB controls instead.

The ECHO was supplied to us with no recommendations for what ABO Rh controls or weak antibody controls to use. The Capture-r 3 cell screen has a pre-bound sensitised cell that is meant to control each test.

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Hi Rashmi,

I am intrigued by the retrospective analysis your wk antibody qc prompted, that there was a problem with inadequate plate washing. In retrospect, you feel that the inadequate washing caused missed antibodies, correct? Could you tell me a bit more about what Immucor actually did to improve the plate washing for you, and have you observed any connection between issues with plate washing and false positive results??????

Thanks,

linda

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Hi Linda,

I think the problems with the plate washing contributed to poor antibody detection/ missed antibodies. We also had a camera change and washer change, neither of which solve the antibody detection problems. It was only after an improved assay was implemented- this removes the plasma prior to the wash cycle, that detection was optimised.

So far we have not had any further problems but we will still continue to monitor this.

We have not noticed an increase in false positives compared to before changes were made. Are you thinking along the lines of inadequate washing leading to +++false pos rather than false negs?

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hi Rashmi,

I think the answer to your question is.....sort of.....I'm thinking possibly both.....Here is the scenario...... in March/April, I noticed several patients that were presenting as DAT negative, probable warm auto antibodies when run on the ECHO, but if I had them repeated in tube, (both PEG and LISS, and also did complete tube DAT), all was negative. After much back and forth with Immucor Tech support, who were quite insistent that nothing was wrong with the assays, I finally got them to dispatch service because we started to get random errors during testing which indicated the system was not delivering or detecting reagents/specimens that had plenty of volume for processing. After 2 days of going over things, the ONLY concerning finding was that during one of the test cycles of priming the fluidics, PBS was dropped onto the plate deck where the stripholders are lined up for pipetting. This was with both the current and a brand new probe. After long thought out consideration by field service, several parts were ordered. One was a tiny board that controls the probe pipetting mechanism. This stopped the errors we were receiving regarding the level sense.......

Now, why do I think this is relevant? Since this part was replaced, I have not seen any more of these solid-phase related DAT negative, all screen/panel cells positive cases, that were negative in tube (PEG and Liss.....)....thus removing cross contamination and this type of false positive ID's......What do you think?

Linda

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Hi Linda,

We do see batch to batch variation in the number of false positive screens by Capture,-could this have been the actual cause of your problems? . When you realise this maybe the problem, the batch changes.This is the same with the false negative reactions we were getting.

I have not come across the problem you had with the ECHO (yet!), but during a validation last year on the Galileo, there was a complete row on the capture plate that had not been aspirated correctly, with PBS remaining in each well at the end. This was interpreted by Galileo as screens negative.

It would be really useful to get a manual capture user to help us with trying to identify the cause of these problems. The wash efficiency could be varied, concentration of indicator cells etc.

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We have 2 full sets of reagent racks for our Echo. We rotate them out every 12 hours (8 am/ 8 pm) and run QC at that time. We only transfer the Indicator cells from one set to the other.

We decided on 2 sets because we would not use up all reagents within 72 hours if left on the analyzer. Rotating has worked well. The reagents are stable until expiration on bottle this way.

Joint Commission says each bottle must be QC'd on each day of use, so that is why we run QC twice/day.

Linda Frederick

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Hi Rashmi,

Good thought about lots, I did consider it. However, we have been on the same lot number for several weeks since the service call, and still saw the decline in occurrence....in fact, not ONE case within that scenario has occurred......we will be switching lots in the next week or so......we'll see what happens...

I guess I am wondering about the potential of carryover/cross contamination and it's affects on the assay should any problem, however minor, take place in the fluidics (can't help myself, I was a Chemistry supervisor before coming to Blood Bank).....please also note that during this whole time of errors and troubleshooting, WB corQC reacted as expected, and there were no QC errors attributed to this issue. Thus begs the question, is there a testing result pattern that can clue one in to the potential malfunctioning of the ECHO????:confused:

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Hi Linda

f you want to investigate potential carryover, try running an anti-D immunoglobulin in place of a sample, with saline in 5 or more sample tubes after this. This might give you an indication of fluidics problems involving poor washing.

Do you perform strip weighing daily? This slightly flaffy process is meant to show that the washer is aspirating correctly.Looking back on some of our daily records- has shown that staff on occassions have had to repeat this a few times before achieving the correct figures...which seems to defeat the object of this test regime, it's as though we are performing this weighing until the weights comply to the pre-defined figures. At this point we involve the company to investigate.

I am also beginning to wonder if the supplier antibody controls being run are adequate.

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  • 6 years later...
On June 11, 2009 at 0:02 PM, jcoburn said:

We have the Echo and run the WB control once per day of use for group and screen. We only do the weak-D control if the assay is used on the machine that day.

jcoburn, do you use WB corQC for bench QC as well? Same ABO reagents, but different screening cells.

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ElizabethP,

We recently switched to the Echo and I tried running the WB corQC in tube and the only positive (antibody screening) I was able to detect was in screening cell 2 with anti-D.  This didn't react at all with cell 1 (also Rh positive) as well as negative reactions with the c antibody sample.  I ended up ordering the other corQC kit just for positive antibody QC.  I don't understand these results, but it is what it is.

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