Labelling NK Cells with Anti-CD56

I use the anti-CD56 antibody at a dilution of 1/100 to check the purity of my sample after performing a NK cell isolation from PBMC. I perform a 20-minute incubation at 4°C and then read the fluorescence by flow cytometry. I also use it to label NK cells among a pool of various cells that I have incubated together. It works perfectly; I can select specifically my NK cells for further analysis.