CryoStore diary - Oleksandra Hubenia

Secondment at NMBU, Norway | November 2025

In November, I spent one month at the Norwegian University of Life Sciences (NMBU) as part of my CryoStore secondment. During this time, I focused on bovine oocyte vitrification, cryoprotectant diffusion analysis, zebrafish reproductive techniques, and Raman-based assessment of cryopreserved samples within my ongoing research framework.

At NMBU, I worked together with Paulina Pyrek (CryoStore DC) in the group of Prof. Anette Kristine Krogenæs on bovine oocytes. I learned the practical workflow of bovine oocyte vitrification and participated in post-thaw fluorescence microscopy analysis, with particular attention to lipid composition and structural changes after cryopreservation. In parallel, we analysed the diffusion behaviour of cryoprotective agents in these large reproductive cells, linking vitrification protocols with permeability and transport dynamics.

In addition, I gained hands-on experience in zebrafish reproductive techniques under the guidance of Prof. Ian Mayer and Dr. Amin Sayyari. This included ovarian tissue collection, tissue digestion, preparation of material for downstream analyses and zebrafish sperm collection and quality assessment using CASA systems.

I also utilised the BioSpec Raman infrastructure at NMBU (Prof. Achim Kohler) to analyse cryopreserved samples and to validate the performance of my diffusion chamber system on relevant biological material. These measurements enabled molecular-level evaluation of cryo-induced alterations and supported verification of CPA diffusion dynamics under physiologically relevant conditions.

Overall, the secondment allowed me to apply CryoStore concepts across different species and biological systems, combining vitrification, diffusion analysis, reproductive models, and spectroscopic evaluation into a single integrated workflow.

- Sasha