Storing Stem Cells in Liquid Nitrogen or VaporThere are two different ways to store stem cells: in "full liquid" (that means that the tank is full of liquid nitrogen and -190º Celsius) or in "vapor" (that means that the specimens are not in the liquid, but rather in the vapor from the liquid, stored at -130º Celsius). There are pros and cons to each storage method, but the industry standard is changing to vapor.
Although temperature maintenance used to be better in full liquid, new storage tanks have been significantly improved and now vapor tanks are able to maintain a consistent temperature throughout the tanks.
The New York Blood Center, which stores stem cells from the placent and umbilical cord blood for Americord's CordAdvantage product, has begun storing specimens in vapor as we are now confident of temperature control using this method. Our tank's temperature is monitored electronically with readings every hour and we have back-up alarm systems should the temperature be compromised in any way.