In May 2022, from the 9th to the 13th a practical course took place in which a young researcher Kateryna Tarhonska from Poland (NIOM) participated. The S&T COURSE EVENT 7a “Advanced 3D models: ALI co-cultures and liver spheroids – application of the comet assay” was organized by Norwegian Institute of Air Research (NILU). The one-week course was very intense and full of impressions. Firstly, we had a practical training in preparation of advanced ALI co-culture model and 3D HepG2 spheroids. Seeding cells required good laboratory skills, and I really enjoyed seeing the first successes in this process. Secondly, it was very interesting to carry out the exposure of ALI co-culture with nanomaterials in the VitroCellTM cloud system. The assessment of cytotoxicity in exposed cells was evaluated by AlamarBlue. I had the pleasure to get acquainted with an enhanced Comet assay to analyze specific DNA damage caused by oxidative stress. I learned a lot of interesting tricks while doing the Comet assay. Moreover, a multi-pass approach will definitely be implemented in our laboratory. I cannot fail to mention and say thank you for the nice atmosphere and commitment of the employees at NILU. The week-long course provided me with a lot of knowledge, emotions and unforgettable impressions.