Thu Apr 14, 2016 6:52 pm by GregBehbehani
Thanks for posting (and publishing) this!
I have seen a similar background population in human bone marrow, however, I primarily saw the background binding before intracellular staining, but after red cell lysis using the Smart Tube protocol (the heparin from the blood collection would have been washed away). The cells I saw were obviously not real as they were brightly positive for most everything in my panel, so I gated them out assuming they were debris. Interestingly, the cells were only about 1% of total events in normal bone marrow, but much lower (and often completely absent) in patients with AML. The experiment was barcoded so the abnormal events were most likely cells at some point to have been correctly barcoded. This is potentially consistent with an eosinophil population, or at least some other mature cell type.
I'll try your protocol on my samples and see if I can remove the background staining and, if I can clean it up, what normal population comes back after those cells are restored to normal staining.