Validating/qualifying a liquid nitrogen cryo vessel for recombinant cell storage

I have recently joined a new company and we are validating everything from scratch. We are using a recombinant cell line to produce an API.
I have been put in charge of validating/qualifying the cryo vessels we use to store our cells in.

I have no idea where to start so any advice would be much appreciated.

Hi Charl,

This could be quite a bit project.

The starting point would be to find out if a URS - User Requirement Specification exists for this equipment. This would usually be the starting point with any validation study.

If you don’t have initial requirements it could be difficult to draft the remaining documents you need plus generating a testing phase protocol would be impossible as you have no requirements to test against.

Other people may have other approaches.


Hi Charl,
I would also include details of the requirements (related to your scope of use of these vessels) regarding the immediate environment in which these vessels are to be situated within your URS documentation. I can imagine that the procedure for insertion and removal of cells from these vessels will be as tightly controlled as their storage. Therefore, I would think that requirements for the immediate environment should be equally tight.
As an example, which may or may not be applicable in your case, your requirements around this may be as simple as a cleanroom being validated to whichever classification is stipulated in your process. However, there may be requirements not covered by cleanroom classification that you may wish to include also. So these may be captured in your cryo vessel URS documentation instead.
Hope this is of some help,


I was also a bit worried about the liquid nitrogen itself. Here in South Africa we only have industrial liquid nitrogen available. A truck basically stops at the receiving area and fills the liquid nitrogen containers which are then used to top-up the cryo vessels. This is a big concern for me as this is could be a huge source of contamination as I have no idea under what conditions the previous consumers vessels where topped up.

I found an article (Validation of Sterile filtration of liquid nitrogen, Leesa D. Mcburnie and Barry Bardo) where they validated the filtration of liquid nitrogen.

Do you think this is a bit overkill?
Would it be sufficient to just validate that the contents of the cryo tubes remains sterile in the liquid nitrogen as long as the tube seal remains intact?


a lot of information can be found in the ISPE website: It is wise to be a member of the ISPE. There are also member fora that could help you. :slight_smile:
some points to address:
A nitrogen cryovessel is some kind of a freezer so therefore if you look in that perspective. you should qualify it like a freezer;
A vapour phase systems works like a heat pump:
energy (heat) leaking into the tank is conducted down to the liquid via hte racks. this energy is absorbed by the liqueis as it vaporises, cooling the tank to an equilibrium. The tank lid is the ony non-vacuum insulated surface, is the main paht for heat leak. Therefore a narrow neck vessel has a lower heat leak than the width neck vessels.
please remember that the cells will freeze in the gas phase of the LN and not in the liquid phase.
I will point out some important thinks you should qualify:

volume of the vessel amount of racks should be oke and the way it is stored above the Liquid phase.
lid should be be able to lock
light in the vessel
temperature gradient in the gas phase
volume alarm (to much LN or to less LN)
temperature alarm
open lid alarm (time should be predetermined)
data aquisition of the temperature system
callibration of the temperature probes on different levels in de vessel
documentation needed for electrical schemes, alarmen as build test ect
SOP for storage, maintenance filling procedure ect
hopefully I give you some appropriate answers
it is not that much of a work the difficulty is in to find callibrated probes for these low temperatures. :cool: