Asymptote has launched an innovative nitrogen-free freezer that it says could transform the field of embryo and stem cell freezing
The nitrogen-free freezer is the first piece of controlled rate equipment which does not use liquid nitrogen to freeze cells used in IVF.
A study reporting a good survival of human embryonic stem cells, mouse embryos and human sperm frozen in Asymptote's freezer has been accepted for publication in the journal Reproductive Bio Medicine Online.
Conventional controlled rate freezers are cooled by liquid nitrogen.
But these are inconvenient to use and puts samples at risk of contamination from liquid nitrogen-borne bacteria.
Laboratories which operate under sterile conditions, or require high air quality, should avoid the use of liquid nitrogen freezers, for example laboratories freezing cells for use in cell therapy.
Asymptote has taken technology from aerospace and military applications and used it in its freezer.
The Stirling Cycle engine is a compact electrically powered cooler that can reach temperatures of -100C, low enough to cryopreserve cells.
This unique technology removes any risk of contamination to samples and means the freezer can be used in cleanrooms.
"A lot of people don't realise that bacteria and debris material are found in liquid nitrogen," says Asymptote's director John Morris.
"Liquid nitrogen freezers can potentially contaminate samples and shouldn't be used in cleanrooms".
"The nitrogen-free freezer can".
Although alternative refrigeration methods are available, such as Peltier modules and mechanical compressors, they either lack the cooling ability or are too large and cumbersome to be suitable for use in laboratory scale cryopreservation equipment.
The freezer is small and simple to operate.
It does not have the problems associated with storing and handling liquid nitrogen, and the running cost of the nitrogen-free freezer is estimated to be just 1% of a liquid nitrogen freezer.
Studies are also being carried out on horse sperm and have shown the freezer's ability to freeze larger volumes of cell suspensions in bags.
The freezer can be used either in the laboratory or as a portable device powered from a car battery.
This makes it ideal for veterinary and conservation work where the need for large amounts of liquid nitrogen has previously hindered collections and experiments in the field.
Asymptote is a specialist in controlled solidification research and product development, based in Cambridge, UK.
Its products and process technology have resulted in significant advances in disciplines ranging from human and veterinary IVF to the food and pharmaceutical industries.
