Microbial occurrence in liquid nitrogen storage tanks: a challenge for cryobanking?

Modern biobanks maintain valuable living materials for medical diagnostics, reproduction medicine, and conservation purposes. To guarantee high quality during long-term storage and to avoid metabolic activities, cryostorage is often conducted in the N vapour phase or in liquid nitrogen (LN) at temperatures below - 150 °C. One potential risk of cryostorage is microbial cross contamination in the LN storage tanks.