Abstract: A method of vitrifying mammalian cells. According to the method of the present invention, biological cells of mammalian origin are frozen quickly by a vitrification method. Upon exposure to a coolant, the biological cells undergo vitrification. The biological cells which have undergone vitrification may be stored for a period of time and then devitrified at a later date. The devitrified biological cells remain viable. Preferred biological cells according to the present invention are developmental cells including blastocysts, embryos, and oocytes.

Abstract: A procedure for cryopreservation and efficient post-thaw recovery of a single or few cells, preferably human spermatozoa, their precursor cells or blastomeres, which is achieved by injecting cells into cell-free mammalian zonae pellucidae. The cells may also be of any other type where there are provided a relatively small number of valuable cells which must be retrieved. The zona pellucida may be cryopreserved with the cells contained therein. The method involves a combination of physical micromanipulation procedures and cryoprotectant mediated cryopropreservation. The zonae may be tracked by positioning them into straws between two small air bubbles prior to preservation. There is a high recovery of zonae and sperm within the zonae, and a high fertilization rate of the sperm using ICSI after recovery.