Vitrifying and Warming of Human Oocytes, Embryos, and Blastocysts: Vitrification Procedures as an Alternative to Conventional Cryopreservation. 
The important principle of cryopreservation for mammalian embryos is to reduce damage caused by intracellular ice formation. 
http://www.cryotechindia.com/vitriproto.htm 
It is perfectly effective and highly clean. It’s the simplest protocol.Everyone can get 100% post-warm survival for oocytes, embryos and blastocysts, and the highest pregnancy rate! 
Cryotec is a special device that allows to minimize the volume that will be cool and warm with a result up to 100% of survival for oocytes and all the stage of pre-implantation embryos. 
Vitrifying and Warming of Human Oocytes, Embryos, and Blastocysts,oocyte vitrification protocols,embryo vitrification protocols. 
http://www.cryotechindia.com/warmproto.htm