Historically, laboratories have performed alloantibody titers in pregnancy in parallel meaning the current sample is tested concurrently with the previous sample. The intent is to accomodate for variations in technique and technologist. In my experience we very rarely see a titer that is more than one tube different from the previous sample. Has anyone dropped performing titers in parallel? What has been your experience?

Certainly not.

It is performed not just to smooth out variations in technique and technology, but also because there can be a wide variation of antigen expression from one individual's red cells to another.

These are on the same patient, correct? How could the antigen expression widely varry?

Maybe I am brain farting here????

Malcolm means variation in antigen expression on the cell used to perform the titer. Thank you Malcolm. I should have also included that in my explanation.

YUP----Brain fart

BraYUP----in fart

We've all done it. My brain has suffered from chronic flaulence for decades!!!!!!!!!!!!!!!!!!!!!!

We do not test the last sample together with the new sample. On the other hand we do use the same erythrocytes for almost every titration (frozen cells). When we need a new titration cel we do extensive antigen strength comparison before we change.