Microbial contamination of embryos and semen during long term banking in liquid nitrogen

Embryo Vitrification on Day2 at 4-Cell Stage Using Cryoloop Device: Our Experience.

“…There have been published reports of embryo cell damage and poor survival of thawed embryos [17,18,19]. Experiments have shown that there is a theoretical risk of bacterial and virological contamination of cryopreserved embryos in the liquid nitrogen during cryostorage, though no such risks have been demonstrated in humans [20,21]. Studies on cryopreserved embryos demonstrated that the cryoloop device can be used for embryo cryostorage by supercooling the air inside the cryovial.…”

Comparison of vitrification and slow freezing for cryopreservation of cleavage stage embryos (Day 3) and its impact on clinical outcome

“…The risk of cross contamination in liquid nitrogen storage containers even at -1960c has been widely debated (Bielanski et al 2003), but no studies have demonstrated unintentional uptake by a human embryo of any pathogen during Vitrification even with the use of open systems. 24 We select cleavage stage (Day 3) embryos for Vitrification in our study. Though there are few studies on day 3 embryo vitrification.…”

The Problem of Contamination: Open vs. Closed vs. Semi-Closed Vitrification Systems

“…There is evidence that frozen samples in hermetically sealed straws are not contaminated even if they are in contaminated containers with contaminated LN2 and LN2 does not contaminate infective biological samples that were frozen in a sealed container (13,14) (cryotube, straw, etc.). It is very important to disinfect and clean the container before filling it with LN2 (16).…”

“…It means that we will freeze the sample and we will deposit it for a long storage until thawed and used. Normally the LN2 cooling solution is the most widely used in cryopreservation and survival of pathogens at high temperatures (-196 º C) has already been proven by many studies (1-3,27,28) cases also involved in seeing cross-contamination of human papillomavirus (14,29).…”