Arav A.,FertileSafe |
Saragusty J.,Leibniz Institute for Zoo and Wildlife Research
Animal Reproduction Science | Year: 2016
Directional freezing has now completed 30 years of development since it was first introduced to cryobiology. In the field of sperm cryopreservation, directional freezing has been shown to be advantageous over slow freezing for numerous domestic and wildlife species. In particular, it was shown that freezing of large volume is possible. Furthermore, double freezing of sperm and freezing of sex-sorted sperm are possible and became the routine in the sex sorted sperm industry. In wild animals, our labs and others showed that sperm from a wide range of terrestrial and aquatic species can be successfully cryopreserved using directional freezing. Finally, we will describe for the first time the successful freeze-drying of human sperm in an aseptic method. Using a device that produces clean liquid air, we froze human sperm in small droplets and then dried them in a bench top lyophilizer that was sterilized prior to use. More than 80% of DNA integrity was found after rehydration. © 2016 Elsevier B.V.
Theriogenology | Year: 2014
Two hundred years have passed since the first description of supercooled water by Gey-Lussac to the recently high survival rates of embryo and oocytes after vitrification. This review discusses important milestones that have made vitrification the method of choice for oocytes and embryos cryopreservation. We will go through the first cells ever to survive low temperature exposure in the beginning of the last century, the finding of glycerol in the late 1940s and the first mouse and bovine embryos freezing in the 1970s. During the1980s, embryo vitrification began and the time since is a tribute to the development of oocytes vitrification. Standardization and an automatic vitrification procedure are currently under development. The next evolutionary step in oocyte and embryo cryopreservation will be preserving them in the dry state at room temperature, allowing home storage for future use a reality. © 2014 Elsevier Inc.
Arav A.,FertileSafe |
Advances in Experimental Medicine and Biology | Year: 2013
Vitrification is a physical process by which a liquid is transformed into a solid of amorphous glass form. It was only at the end of the nineteenth century (1898) that Gustav Heinrich Johann Apollon Tammann pointed out that a large number of substances can be obtained as glasses and suggested that this property might be universal (Tammann, Zeitschrift for Physikalische Chemie; 25: 441479, 1898). Basically, Vitrification is the supercooling of a liquid to a temperature at which the viscosity is so high that it can be defi ned as being at a solid state. The understanding of the Vitrification process has been deepened over the years and has been applied for cryopreservation and currently is the method of choice for preserving oocytes and embryos. © Springer Science+Business Media New York 2013.