After detaching the macrophages for flow cytometric analysis, I noticed that the washing and centrifugation steps take a long time. Can I shorten the spin time to 10 minutes at 350 x g?

Spinning the cells for 15 min at 350 x g has been proven and tested by PromoCell Research & Development. The QC department uses these settings during testing. Any lower centrifugation value (g-force and/or time) will lead to significant cell loss by means of non-sedimented, but intact, macrophages.