Complement Check Cells

[Gkloc]

Does anyone else here use Immucor's Complement Check Cells? If so is anyone having a problem with them? And is there any other company that makes these cells that anyone is using? We've been having a problem getting them to come up positive for awhile, at least macroscopically, sometimes they are really weak or we have to look at them under a scope. Thanks for any help

[David Saikin]

I don't believe any one else manufactures Complement Check Cells. Using tubes, I always had to struggle to get them to react 1+. I use them in gel now - always 4+.

[KarenJ]

They are very weak in tubes, 1-2+ is about as good as it gets.

[clmergen]

I let them sit for 5 minutes, just like I would a patient, that helps a lot to get it to 1-2+.

[Dr. Pepper]

As does a very gentle hand resuspending.

[Gnapplec]

We've been using those cells for a long time and they sometimes barely give a 1+ for our positive QC. Just like the previous two posts, our SOP has us incubate them for 5 min. ( and yes gentle resuspending is key )

[David Saikin]

. . . BUT - do you resuspend your C-DAT the same way as your "gently" resuspend your check cells? - (rhetorical question)

[Dr. Pepper]

Rhetorically, we all resuspend gently. Alas, in the real world, it's yet another reason to get away from tube testing, where you can have one tech seeing things that aren't there and another who beats the **** out of the tubes and doesn't see things that are there.

[Gkloc]

I figured as much I just wanted to see if everyone else who was using them was having the same issues. Sometimes it'll be a weak 1+ and sometimes it's not even a very strong weak reaction if that. We incubate the tubes for 5 minutes also but that still doesn't seem to help sometimes even. Thanks for the feedback

[AMcCord]

The product insert says "NOTE: Agglutination by anti-complement is seldom as strong as that customarily seen with anti-IgG and is more readily dispersed." The insert also goes on the say that reactivity will diminish over the dating period of the reagent. They aren't kidding. It sticks in my mind that I read, or was told, that the expected reactivity is 1-2+. It may have been in an old product insert or from a conversation with tech support at Immucor ... just can't remember. Gently shaking is the key - for patient tests, too. You might also find it helpful to switch to the new lot of Comp Control Cells as soon as they come in, instead of waiting for outdate of your current lot. We have quite good luck with fresh lots - often 3+, if shaken nicely.

I use these cells as a tool to check the 'shaking' habits of techs and students. I have convinced even the most persistant vortexers that it does make a difference in what they see.

[Sue Miller]

We also have the same issues. We keep the cells in the refrigerator when not in use. I also split my monthly shipment receiving 2 vials in one shipment and then 1 vial in a second shipment 2 weeks later, trying to have fresher reagent in use. Quotient is working on a C3 check cell prep kit that will allow you to make your own in house, which should be much stronger since the 28 day expiration will start there instead of at the manufacturing facility.

Looking foward to whenever that is ready for release.

[AMcCord]

Yes, I agree, refrigeration when not in use is definitely helpful.

[ltechlin]

I don't believe any one else manufactures Complement Check Cells. Using tubes, I always had to struggle to get them to react 1+. I use them in gel now - always 4+.

Are you using Ortho Gel cards? I could swear that the Ortho rep giving a demo last month told us that they don't have a complement card for DATs in gel? I thought that they only had polyspecific and AHG cards. I thought the rep said at her old hospital, when doing a DAT, they sent out the test if the doctor wanted the complement component by itself.

[nmartin]

We have the same problem with very weak results. Our solution has been get our standing order every 2 weeks from the supplier instead of once a month. The fresh lot # works in the instances we can't get the first lot # to agglutinate.. Talk about a marketing ploy !!

[David Saikin]

YES - but I use the buffered gel card with 50uL cells (0.8%) and 25uL anti-C3b,-C3d. I also run the pt cells with diluent, just to make certain I am not seeing any non-specific agglutination. I don't do enough DATs to justify the anti-Comp cards (there are anti-Compl cards available if Ortho doesn't have them, but not for use in the US - yet).

Are you using Ortho Gel cards? I could swear that the Ortho rep giving a demo last month told us that they don't have a complement card for DATs in gel? I thought that they only had polyspecific and AHG cards. I thought the rep said at her old hospital, when doing a DAT, they sent out the test if the doctor wanted the complement component by itself.

Edited October 27, 2010 by David Saikin
more info added

[Barbhara]

We use them, and I am not aware of anyone else that makes them. Are you incubating at Room Temp for 5 minutes prior to spinning them?

[David Saikin]

I do incubate my gel cards for 5 minutes prior to spinning.

We use them, and I am not aware of anyone else that makes them. Are you incubating at Room Temp for 5 minutes prior to spinning them?