Varying amount of complement to cells when sensitised in vitro

[Emma P.]

Hello everyone,

The recommended  methods (FDA 1992) stated that for preparing of complement coated red blood cells the amount of complement to cells vary from donor to donor.

So when I have C3b / C3d sensitised red blood cells of different donors ( via Fruitstone method according to the recommended methods) and doing a potency this potency vary from 1:4 to 1:128.

Does anyone know how to explain that? Are there any literary referrals? Is there a varying amount of complement in plasma or varying amount of C3- receptor on red blood cells?

Many greatings

Edited November 11, 2018 by Emma P.

[exlimey]

I'm sure there are lots of variations between both Complement content of sera and the number "binding sites" on red cells. I suspect others on this site can provide references.

This is assuming you are using the same antiglobulin reagent each time: To even out the variations, I suggest you use a pool of Complement sources (3 - 5). You may also consider using a similar pool of red cells. This may help lot-to-lot consistency. Ideally, in a perfectly-controlled world, one should use the same Complement source(s)and red cell source(s) each time you prepare a batch.

[noelrbrown]

Can you explain further the potency statement  "doing a potency this potency vary from 1:4 to 1:128."  Do you mean with a AHG containing anti Complement?