The two-month internship (from March to April 2020) at University of Jyväskylä, Finland offered me critical knowledge about stable isotopes and their application in aquaculture nutrition research. I had the opportunity to manipulate isotopic analysis preparation for feed ingredients as well as fish tissues and use Mixing model (MixSiar) to determine nitrogenous contribution of some ingredients to fish tissue. The internship was funded by IP Development of Internationalization JU 2019–2020.