Give it a moment or two.

[Oh, that question means that at least part of the blood is working. Alucard sighs, fond and absolutely not surprised that this is where the discussion has ended up. It'd be weirder if it didn't.]

Only if it's being carried in a container or the like for an extended period of time. I can't feel it moving in your system, for example. Not as fun an answer as you were angling for, I know.