We have recently experienced several cases of seemingly strong positive reactions on gel that prove to be negative with tube testing. Has anyone else had similiar experiences?

It has been my experience that the problem isn’t really with the gel but with the Ortho 0.8% cell suspension. Apparently there is something in the mix that some patient’s just don’t like. If you were to take another manufacturers screen cells and mix them to a 0.8% cell suspension with the MTS deluent you will find the result are usually also negative.

Just how strong is your reaction? We have started storing our reagent racks in a black box. Our Ortho rep said that eposure to light and room temperature could cause degradation of the cells. For us, portecting the cells from light has helped significantly. That and we keep our toes crossed while we add the cells to the gel card. I still have concerns that one day a tech will ignore a weak reaction in gel and it will be a clinically significant antibody.

:handshake

We had this problem a lot too, however, since we went live on the Provue, we have not seen the problem. I believe that keeping the cells out of the light and refrigerated as much as possible is a good solution. The provue is dark inside and we switch out reagents every shift. So, try keeping the cells covered and put them away as much as possible.

Gel is much more sensitive than tube so I wouldn't compare the two .... we go down in sensitivity to gel when we need to get rid of a high titre cold or auto (gel seems to pick up more of these).

Making the 3% to 0.8 % and running in gel has become a parit of our work up for weak reactions and negative panels.

Recently we have experienced multiple antibody workups with negative reactions using the LISS tube technique, PEG tube technique and 22% albumin technique but the GEL was positive. We prepare all of our 0.8% panels using Immucor, Ortho and Medion panel cells. Recently we had a workup where 26 to 39 GEL cells tested were 1+ to 2+ but all tube testing was negative. A titer performed in GEL was 2 and 0.2 MDTT treated cells tested in GEL were no different than the "neat" testing. Our client had the same findings. Ortho was contacted and they will "try" to get back to us within a week; that would be by today, no response yet. Any ideas?