Who pays for the analysis?

The person who wants to see the results.

This could be you, independent of a donor referral, because you want to know if you have had vaccine transmission, or because you want a before and after status to see if your therapy worked. Then you are the one who pays.

Or the recipient of a blood donation wants to verify that your blood as a donor and member of SafeBlood is really free of mRNA residues. In this case, the recipient wants you (as a donor) to analyze your blood before the transfusion, ideally at the same time as the donation. Since the recipient asks for the result of the analysis, they should also pay for it.

For you as a donor, this has the advantage that you receive a verified donor status free of charge. As compensation for your donation, so to speak.