Photo-released chemokine is functional. (A) Evaluation of functionality of photo-released chemokine in a transwell chemotaxis assay. The bottom chamber was loaded with supernatants from cells transfected with a mock plasmid or Cxcl2-YFP-2xUVR8 or constitutive Cxcl2 and then photo-activated or not. Freshly isolated mouse neutrophils were placed in the top chamber. (B) Number of neutrophils transmigrated over background migration (determined by migration to mock supernatants). Data points represent multiple wells within 1 experiment representative of 4 independent experiments. Unpaired t test was applied.