We occassionally have problems with PeG testing where the check cells fail.  These are the high protein plasma's that turn super cloudy when PeG is added.  Handwashing and "flicking" the cells off the bottom of the tube inbetween washes helps some, but some are really stubborn and just won't check.  Does anyone else see this and what do you do?   thanks.

if you are washing by hand  you should probably add an extra wash.  (maybe you should calibrate your serofuge for PeG washes too if you have that much problem resuspending the cell button). 

 

If you use automated cell washers, some do not wash PeG tubes efficiently. 

Thanks for your ideas David.   To clarify what I wrote, we do have automated cell washers, but with these samples the buttons get super stuck to the tubes and the check cells never work. So techs are instructed to repeat testing and wash by hand so the buttons can be re-suspend between washes and give them an extra wash.  Occasionally though, even this doesnt work.

We usually wash at least 4 times when using PeG (whether using cell washer or hand washing).

Thanks for your ideas David.   To clarify what I wrote, we do have automated cell washers, but with these samples the buttons get super stuck to the tubes and the check cells never work. So techs are instructed to repeat testing and wash by hand so the buttons can be re-suspend between washes and give them an extra wash.  Occasionally though, even this doesnt work.

 

Are you using plastice tubes?  I don't know if it makes a difference.  I use glass 10x75s and wash 4x by hand.  Usually no problems.

When we had Baxter cell washers (CW2) we had the same problems.  We now have Helmer cell washers and they seem to do well with PEG.

When we had Baxter cell washers (CW2) we had the same problems.  We now have Helmer cell washers and they seem to do well with PEG.

 

That's interesting.  Any idea why the Helmer cell washers seem to do better?

 

Donna

We were seeing the same thing with Lo-Ion lately.  We didn't contacted the company as we were switching to a new company for reagents. 

Donna,

 

My only guess (and its only a wild guess) is that the Helmer must mix the cells better between cycles.

Donna,

 

My only guess (and its only a wild guess) is that the Helmer must mix the cells better between cycles.

My guess also

Helmer does agitate  between washes. I thought that was standard for wash cycles.

When I worked in a reference lab, we had certain patients that we just always tested using LISS rather than PEG for exactly the reason you mentioned.  The PEG seems to cause precipitates.

Some patient samples just don't work with PEG. We would switch testing to, perhaps, tube Saline IAT.

Hello,

I just encountered this problem over the weekend.  I used LISS to resolve the issue as per our protocol.

PeG can precipitate plasma proteins. You may have better results with serum. We use 12x75 tubes and usually have no problems with our old Centra W cell washers x 4 washes. Once in a while we might have to add an extra wash. We have also seen rare patients who just don't want to check no matter what you use for enhancement. One we actually had to wash through 3 cycles of 4 washes before the cells would check. You hope the antibody hangs on tight.