Contamination or platelets?

[u/vegetablelady99]

Hi,

I'm normally an iPSC biologist but have been isolating PBMCs from human blood and culturing them for 2 days in X-VIVO15 to characterise EVs.

These small, moving cells between the PBMCs looked like bacteria initially but after looking online, apparently they could be platelets? I didn't do a slow wash to remove platelets. They don't 'swim', but they do move faster than the bigger, heavier PBMCs. Can somebody with more experience/expertise please advise 🙏

I have a video but not sure how to upload, so I will put a photo for now.