Does anyone use 4 drops of plasma and no potentiating medium when doing Coombs Phase Crossmatches for patients with clinically significant antibodies? I was told that this is accepatable practice but can not find anything in writing to back it up. Thanks.

Most of the literature for "enhancing" antibodies talks about increased serum / cell ratio. This would be one such technique such as enzymes etc......

Does anyone use 4 drops of plasma and no potentiating medium when doing Coombs Phase Crossmatches for patients with clinically significant antibodies? I was told that this is accepatable practice but can not find anything in writing to back it up. Thanks.

In rare cases we will perform a tube IAT using normal ionic strength saline (NISS), rather than low ionic strength solution (LISS), with a greater volume of patient's plasma than NISS suspended red cells, so yes, but it is quite unusual nowadays.

If you can get hold of any old textbooks (circa 1960-1970), you should have no problem finding that this was acceptable practice (and still is in exceptional circumstances).

:):)

We do this for the rare patients who don't like something in the potentiating medium. To approach the sensitivity of using enhancement media, I would suggest extending the incubation period to 60 min. and mixing the tubes a couple of times during the incubation so the settled-out cells get back in contact with the serum. Otherwise, I like the idea of getting the blood out the door quicker with a 10-30 min. incubation with LISS or PEG.

We do the same as Dr. Pepper. LISS is our alternate enhancement medium and we have a few pts that don't like gel or LISS so we use this method.

Question for mjegel1 -

Is there a reason why your lab prefers the "four-drops" technique over the other more commonly-used techniques?

Donna

i believe in Canada they use (or used to use) 6 drops.

Question for mjegel1 -

Is there a reason why your lab prefers the "four-drops" technique over the other more commonly-used techniques?

Donna

Actually, we do not use this method. We use LISS.

That was why I said "used to " - - - I work with some folks from Canada and we have discussed this in the past.