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