What is vitrification?

The vitrification method, which is one of many cell freezing methods, has currently spread all over the world as the easiest-to-use and safest technique. It can cryopreserve oocytes and embryos for many years safely without significant deterioration theoretically. It has played an important role to “stop the time of oocytes and embryos until the precious day that would eventually come,” as a means of fertility preservation and treatment for sterility.

History of vitrification

1949

Polge

Successful cryopreservation for a chicken’s spermatozoa with glycerol--Discovery of cryoprotectant

1972

Whittingham

First successful cryopreservation of a mouse embryo by slow freezing

1977

Willadsen

Establishment of a simplified slow freezing method

1983

Trounson

First reported case of human pregnancy/delivery with a cryopreserved embryo

1985

Rall，Fahy

First successful embryo freezing by a vitrification method

1991

Kuwayama

Successful vitrification of a bovine embryo by the 16-step method

1999

Kuwayama

First successful vitrification of a human oocyte by the minimum volume cooling (MVC) technique

2000

Kuwayama

Establishment of Cryotop Method

2003, 2004

Kuwayama

First successful pregnancy/delivery with cryopreserved oocyte in the United States, South America, and Europe

2012

Kuwayama

Establishment of Cryotec Method

Mechanism of vitrification

As it is often said that approximately 60 % of the human body is made from water, cells contain plenty of water. Water is the only substance in nature for which the volume increases when it is solidified.