I am the cryogenic specialist for a stem cell bank in Greece. I am trying to find the minimum requirements (purity, humidity, etc.) of liquid nitrogen for cryopreservation through controlled rate freezing of biological samples.
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I am the cryogenic specialist for a stem cell bank in Greece. I am trying to find the minimum requirements (purity, humidity, etc.) of liquid nitrogen for cryopreservation through controlled rate freezing of biological samples.
1 Comment
Ian Pope
August 22, 2012I am pretty sure that I could help here – to be honest neither of these factors are important in terms of the delivered nitrogen product. Humidity (water content) is precipitated in the container as ice (which is more sense than LN2) and the purity does not affect the samples since they are only truly affected by the thermodynamic event of the surface atomized liquid and no direct sample interaction occurs.
Humidity from the atmosphere can contaminate opened, cold transfer lines – this can cause issues with the metering / delivery valve on the freezer unit, but there are process controls which can be put in place to minimize this issue.