The present work is conducted in the frame of the EU-funded Graphene Flagship project. The aim is to evaluate the impact of graphene oxide (GO) on the gut microbiome and on the immune system using zebrafish as a model. We previously performed single-cell RNA-sequencing of germ-free zebrafish embryos exposed to GO (sequencing performed at SciLifeLab). We have now performed a follow up experiment using lck-GFP transgenic fish (germ-free) in which the zebrafish were exposed to GO and cells were subsequently sorted on lck and submitted for single-cell RNA-sequencing (at SciLifeLab). We are applying for more storage space as we have already used up most of the allocated 128 GB.