reification, agency

Comrades:
I need some help on the notion of "reification." Is this a
Lucaksian term, or does Marx write about it as well? I'm wondering if
Foucault ever mentions it. I'm assuming his position on it might be
similar to his critique of ideology, i.e. there is always something less
truthful about that which becomes "reified," and that the
unified/unifying subject is the circuit within which this all leads back
to in some totalizing way. Any ideas?

Rich X