Inhibitory effect of unlabeled CCL2 on the binding of CCL2-GFP to porcine monocytes. PBMC were incubated with 25 μL of supernatant containing CCL2-GFP and 25 μL of supernatant from CHO cells transfected with a construct with the sequence of pCCL2 fused to V5-His epitope (CCL2-V5-His) or with InvCCL2-GFP. GFP bound to the cells was detected with Alexa 488- conjugated rabbit anti-GFP IgG. Histograms shown were obtained on gates corresponding to monocytes (CD172a⁺). 6 000 cells were acquired.