NK in a feeder based culture

[Cellval]

Hi all,

 

I have NK cells that were cultured in a G-rex plate with K562 feeders. I will need to verify NK functionality in a kill assay but I would like to not have remains of K562 in my assay. What do you think is the best way to isolate the NK cells in this scenario? We use negative selection for NK isolation from PBMCs but I don't believe it would be a good solution in this case as I think that the debris will just go through the column. 

Thanks!