I have not used CellBIND flasks and so cannot comment on them. However, TC treated surfaces work fine. In addition, I would use plates and not flasks. Depending on how adherent your monocytes are, you may end up having to scrape them and doing this when your cells are in flasks is tedious. The easiest way to detach the cells is to add PBS and incubate the plates at 37 for 10 minutes. Tap the edges of the plate/flask vigorously and the cells should lift off. If they do not, scrape gently. If you are worried about damaging the cells, use accutase.