Laura:  The biggest difference between adipocytes and macrophages is that the latter contains large number(s) of lysosomes/phagosomes in order to digest foreign objects (bacteria, virus, etc).  So, I'd suggest to monitor some lysosomal (acid) hydrolases such as b-hexosaminidase, b-galactosidase, acid phosphatase, etc. in your qPCR assay.  Good luck.

Laura,

I believe that you may run QPCR for macrophage specific transcripts such as CD68, CD16 or CD14. If no significant level of transcript is detected then you can conclude that your cell culture is not contaminated with macrophages.

Thank you both very much for your responses, they were very helpful. I think I will initially look at CD68 to assess macrophage number.