We report gene expression in human neutrophils isolated by two methods: Polymorphprep (~95% purity) and negative selection (~99% purity) from two healthy donors - one donor with low eosinophil contamination of neutrophils and one donor with high eosinophil contamination of neutrophils. We report the effect of the presence of contaminating leukocytes in neutrophil preparations, and in reponse to inflammatory cytokines TNF-alpha and GM-CSF. Overall design: Healthy human neutrophils were isolated using Polymorphprep or negative selection, and incubated for 1h in the absence or presence of TNF-alpha or GM-CSF. RNA was analysed by Illumina HiSeq 2000. The results from n=2 donors were analysed as biological replicates for differential expression analysis.