using cyro tubes?

[pixelhussar]

Hi guys,

I ordered some cyro tubes from here: http://www.brouwland.com/en/

I expected them to attach a detailed manual, but there were only a sheet describing the steps how to add yeasts to the tube and remove the excess preservative fluid with a sterile pipette.

That's OK, but can I put the tubes into the freezer immediately after filling them? Or are they supposed to cool gradually?

Do you have any other tips to use cyro tubes successfully?

Thanks!

 

[daksin]

Unless you have a way to freeze them very quickly (powdered dry ice or LN2) you should just toss them into the freezer. You're using glycerol, right?

 

[SacC]

They look like lab cryovials to me. If you're using them to preserve human cells - I've worked with blood before - then you put your cells in a cryoprotectant and cool gradually, hoping for a 1oC drop per minute. There are special containers containing isopropyl alcohol ('Mr Frosty') for that purpose. Cool slowly to -80 and either store at -80 or move to LN2 is standard. When defrosting, common wisdom is to thaw fast and get them out of the cryoprotectant as fast as possible, because that stuff is probably toxic.

I work in a lab using human cells, that's standard for blood samples - how much of that is necessary for non-mammalian cells is anyone's guess! Slow cooling is probably necessary to prevent formation of large ice crystals, that's what ****s up the viability and that's what the cryoprotectant tries to stop.

 

[brum]

I work in a lab for protein purification, our -80C samples are thrown directly in the freezer. We step it from a -20C to -80C in the event the sample is large enough that it could drastically reduce the overall temperature of the freezer.

Regarding the preservative, I have no idea. I would find some that don't have preservative in them.

 

[senaVZ]

I work in a lab too where we use cryovials. It's best to make sure that if you're using glycerol ( be sure it's sterile also!) that it's at least 15% final volume to prevent any cellular membrane damage. As everyone has said, be sure to do a slow freeze and then have it placed in -80C or liquid nitrogen. Be sure to make sure you thaw quickly because it is toxic. However, my glycerol stocks we usually just scrape it with a micropipette tip( while it's frozen and then place it back in the freezer)and make a streak with that and culture up from there.