Help with quantifying phagocytosis

Dear Imaging Wizards,

I am new to cell profiler and am hoping to get some help.

I’m studying the phagocytosis (eating) of cancer cells (GFP labeled) by human macrophages (mRFP labeled), and the readout is number of phagosomes (i.e. number of holes within macrophages) per field of view.

See image below, which shows the RFP channel: my goal is to get the number of holes inside of the macrophages, as well as the total number of macrophages.

I get good results by counting the number of holes by eye, but this approach is very time consuming.

There are a few things to consider:

  • the size of the phagosome hole varies
  • a single macrophage may eat multiple tumor cells

Any suggestions at all would be immensely appreciated.