Gel vs Solid Phase

[cmiller]

I am interested in opinions about Gel and Solid Phase testing.

Especially anyone that has used both, which do you perfer? Do you think one is easier to use over the other? Ect.

Thanks.

[Franklyn]

We were originally a gel site using the Tecan and Ortho ID MTS system. Our annual transfusion volume (RBCs only) is over 30,000 units a year. The Tecan wasn't a true walk away analyzer and the ProVue was a disappointment. We switched to solid phase when the Galileo was in testing and are now a market site for both the Galileo and Echo. So we have extensive experience with both systems.

In all honesty, the systems each have their own strengths and weaknesses and your mileage with vary with your patient population and the type/volume of testing you perform. The solid phase seems to pickup emerging antibodies sooner than gel but the gel is easier to read manually than solid phase. However, there isn't a real need to read solid phase manually so, that difference is a bit mute.

The solid phase testings biggest advantage is the analyzers are truly walk-away with predicable testing times. The Echo has the added advantage of being pretty quick, but that will soon be passed on to the Galileo with a future upgrade. Overall, based on reactivity, strengths and weaknesses, I would go with solid phase. We published our validation study in an AABB abstract back in 2004 (I believe). If you are interested, you can dig it up and read all the gory details at your leisure.

[David Saikin]

If you are ging to go with an automated system - Provue, Echo, Galileo, Tango - see them all in operation and talk to the users not the vendors. If you want to do manual -gel vs solid phase, - I think you'll find the gel is more flexible, ie, you can do more things easier. I went to gel for a number of reasons - most notably it was easier for my personnel - to learn and to read. I had demos of both. An additional plus was that there were no solid phase users nearby in case I needed to "borrow" something. Everyone I know who has an automated system really likes the one(s) they have. I also have been to a considerable number of transfusion services for professional reasons - I have only seen solid phase in one.

[Mabel Adams]

If you look at the CAP survey results where they report the method used, you see vastly more gel users than solid phase. It will be interesting to see if the levels change due to introduction of the Echo.

[John C. Staley]

Mabel, you'll never know the answer to that if you don't subscribe to the JAT (automated testing) CAP proficiency series. The J series just compares the manual use of the technology and does not take into account the automated users.

[OPUS104]

Donor Center:

We use solid phase to test 6 sample pools of our donors. Pos. pools are broken down and tested individually in solid. These samples are then sent to Ref. for Gel I.D.. We have several donors a week that are pos. in solid phase (many times husband/wife donating on same day) and neg. in Gel and tube(PEG). We are not automated for either system. We have a good deal of "false +" samples from solid and sometimes do not detect donors with 3 year history of antibody until posting. But this can be said about Gel now as well. As usual......everything has its + and =.

[Mabel Adams]

Well, John, that explains a lot. I didn't realize there was an automated survey. Thanks.

[JanineR]

Donor Center:

We use solid phase to test 6 sample pools of our donors. Pos. pools are broken down and tested individually in solid. These samples are then sent to Ref. for Gel I.D.. We have several donors a week that are pos. in solid phase (many times husband/wife donating on same day) and neg. in Gel and tube(PEG). We are not automated for either system. We have a good deal of "false +" samples from solid and sometimes do not detect donors with 3 year history of antibody until posting. But this can be said about Gel now as well. As usual......everything has its + and =.

OPUS: how large are the donor sample pools you test? I'm currently doing some studies on different methodologies (2-cell vs. 3-cell, gel vs. solid phase) to determine which is the most sensitive for detecting Anti-D in pools of 512 and would like to know your experiences with pooled samples for antibody testing.