We have a COBE 2991 and for quarterly QC we check the total protein of the final washed product.  This qc was suggested by an inspector previously.  I am having some difficulty finding a reference for this.  Does anyone have experience with this?  Please advise.  Thank you

Edited October 25, 20195 yr by bstaley

Haven't used one of those in decades;  what does the manufacturer recommend?

Edited October 25, 20195 yr by David Saikin
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Just curious but did the inspector mention why you should check the total protein?   

The whole point of washing RBC products is to remove residual plasma, therefore to verify if said residual plasma was removed, you test the washed RBC supernatants for protein.

We have three COBE 2991s and we use Albustix protein dipsticks for detection. We have a positive control made from diluted donor plasma, and a negative control that is just saline. We sample a segment from the waste line post washing. For positive control you should have a set reading to match based on your protein detection technique, the negative control should be negative, and the washed RBC supernatant should be negative or near negative.

Times and focus change.

Thank you all for your input.  The inspection and process change occurred prior to my arrival.

I contacted the manufacturer and they do not have any recommendations, just stated the norm, that we can create a procedure and must validate it.  I requested stats or testing info to support their claim of 99.8% removal of plasma and have not received a reply yet. 

Thank you,
Brian

If the manufacture has no recommendations I'm not sure that this is a necessary QC/PM process. I've had inspectors suggest something because it's what they do at their lab but that doesn't make it something that is required to be done.  How long has this protein check been being performed and has it ever been positive?

Wouldn't the presence of excess protein cause the Check Cells to not work when added to negatives? If your Check Cells are working during daily reagent QC and whenever you do DATs and/or IATs I don't see the point of the quarterly test for protein. 

Now if you were having a problem with Check Cells not working I would think checking for excess protein as a trouble shooting option would be worthwhile.