Are programmable freezers still needed in the embryo laboratory? Review on vitrification.
The predictable answer to the provocative question of whether programmable freezers are still needed in the embryo laboratory is an even more provocative 'no'. However, such a radical statement needs strong support. Based on the extensive literature of the past 5 years, the authors collected arguments either supporting or contradicting their opinion. After an overview of the causes of cryoinjuries and strategies to eliminate them, the evolution of vitrification methods is discussed. Special attention is paid to the biosafety issues. The authors did not find any circumstance in oocyte or embryo cryopreservation where slow freezing offers considerable advantages compared with vitrification. In contrast, the overwhelming majority of published data prove that the latest vitrification methods are more efficient and reliable than any version of slow freezing. Application of the proper vitrification methods increases the efficiency of long-term storage of stem cells and opens new perspectives in cryopreservation of oocytes, both for IVF and somatic cell nuclear transfer. However, lack of support from regulatory authorities, and conservative approachs regarding novel techniques can slow down the implementation of vitrification. The opinion of the authors is that vitrification is the future of cryopreservation. The public have the final say in whether they want and allow this future to arrive.
Vajta
Gábor
G
Population Genetics and Embryology, Department of Genetics and Biotechnology, Danish Institute of Agricultural Sciences, Research Centre Foulum, DK-8830 Tjele, Denmark. gabor.vajta@agrsci.dk
Nagy
Zsolt Péter
ZP
D000818:Animals; D002970:Cleavage Stage, Ovum; D003080:Cold Temperature / Q000009:adverse effects; D015925:Cryopreservation / Q000295:instrumentation / Q000379:methods* / Q000639:trends; D003451:Cryoprotective Agents; D018562:Disease Transmission, Infectious; D033041:Embryo Research; D004622:Embryo, Mammalian / Q000502:physiology*; D006801:Humans; D009865:Oocytes / Q000502:physiology; D013045:Species Specificity
D003451:Cryoprotective Agents