I have a question for any of you who may be using Ortho MTS gel cards for Rh antigen typing (C, c, E, e). I understand that you need to make a 4% dilution of your patient or donor cells that you are testing in the Diluent 2 Plus. Do you also need to dilute reagent red cells that you are running as your postive and negative controls in Diluent 2 Plus, or can you use them straight from the bottle (since they are already at the right dilution)? Thanks for any help you can give me!

I validated my ag typing using 0.8% cells. I would say you need to dilute them in the cell diluent to accommodate the lo-ionic environment. Are you using the specific ag typing cards? I use the buffered gel with purchased antisera. (50uL 0.8% cells and 25uL of antisera).

Yes, I am looking at using the specific antigen typing cards. But was having a hard time trying to

figure out how to make a 4% suspension of the reagent cells in the diluent without ruining the entire bottle of cells.

Rita, We use the Ortho MTS monoclonal gel cards (C, c, E, e) and take the controls right from the 4% panel cell vials. We only use the Diluent 2 Plus to dilute if we are using patient or Donor cells to test. Hope this helps!

Yes, that is very helpful to know. Thanks so much!

Yes, I am looking at using the specific antigen typing cards. But was having a hard time trying to

figure out how to make a 4% suspension of the reagent cells in the diluent without ruining the entire bottle of cells.

take 500 microliter LISS + 25 microliter erytrociyte... reconstitute and pipet 12,5 microliters to each microtubes. then centrifuge 10 min. finally evaluate... that is all

Has anyone worked out the cost comparison between using the MTS antigen typing cards vs. using buffer gel card with separate reagent antisera and controls vs. doing antigen typing in tube with reagent antisera and cells.

With the buffered gel cards you would be free to buy typing sera from someplace cheaper than Ortho--and there are getting to be a few competitors in the US these days: Bio-Rad, Quotient (Alba) and Hemobioscience, I think. Must validate it in the gel process of course.

I have started the process of validating antigen typing in the IgG gel cards for Duffy and Kidd antigens but need to do a cost analysis to be sure it is really cheaper. One variable I don't know is how many drops (tests) can you get from the 5ml vial of antisera? I've always believed that 1ml=20 drops, so 5ml=1000 drops. Therefore, one 5ml vial would run 1000 tests using the tube method. Using a gel card, it would be 25 microliters which is half a drop (so twice as many tests per vial and half the cost per test). Am I on the right track?

I've always believed that 1ml=20 drops, so 5ml=1000 drops. Therefore, one 5ml vial would run 1000 tests using the tube method. Using a gel card, it would be 25 microliters which is half a drop (so twice as many tests per vial and half the cost per test). Am I on the right track?

If you assume 20 drops per 1.0ml then 5.0ml would perform 100 tests. You are correct in the assumption that 25 ul would allow you to potentially perform twice as many tests. Would hate to see you perform a cost analysis with the decimal point in the wrong place and come to a false conclusion.

Oops! My bad. I know where my mistake is. I was thinking of 50ul instead of 5ml when I initially multiplied. This does make it look much more cost effective now. Thank you Deny.

Kathryn