Hi Long, first of all you must make a distinction between serum-addicted medium (typical mammalian adherent cell cultures and lines) and serum-free conditioned medium (such as normal/cancer stem cell cultures or certain types of suspension cells like hematopoietic stem cells…)

For the first one serum concentrations as high as 90% (no medium, just serum plus the cryoprotective agent such as 10% of DMSO) are sometimes used, may improve their post-freezing recovery and survival

For cells normally grown in serum-free medium, adding from 50% to 90% of conditioned medium (serum-free medium in which the cells were normally grown) to both the cell freezing and the recovery media may improve their post-freezing recovery and survival. The addition of 10% to 20% cell culture-grade albumin to serum-free freezing medium may also increase post-freezing survival. If you are using rare population (i.e. cancer stem cells,) the medium usually contain a supplement (50 X B27) that retain some FBS component and property, that can help post freezing recovery, so you can use this instead of FBS…

I hope it can help you..

Regards

DMSO is cryoprotector that block ice crystal formation. Cells would be dead just in PBS or media. You can use 90% FBS (or KSR) + 10% DMSO. Sometimes researchers use 50% FBS + 40% medium + 10% DMSO. May be you can substitute media with PBS in that case but the change of osmolarity might not be beneficial for freezing.

Actually I would like to know the purpose of FBS in cryopreservation.

I have tested some media to cryopreserve cells and the best way is to freeze them with 90% FBS + 10% DMSO. Doing that you can recover more viable cells.

If you do not want to use FBS due to xeno material content, you can replace it with PRP (platelet rich plasma). In our facility we used 40% PRP, 50% medium and 10% DMSO.

Hello Long,

Above answers have explaied pretty much about ice crystal formation and cell death and role of DMSO as cryoprotectant as these things are necessary to keep your cells viable. But if you ask an alternative to DMSO then you can go for glycols or some starch additives.It is normally advisable to reduce the amount of DMSO to avoid toxicity so you can opt for these alternatives and in case of stem cells you have to extra cautious as sometimes there can be spontaneous differentiation due to fluctuation in DMSO or temperature shock. So for stem cells trust me, don't play much and try to opt 5-10% DMSO with 90%FBS and try to store cells in a controlled vessel like Mr. Frosty.

The use of DMSO as criopreservadores and fetal bovine serum has a priority protect cells against the formation of ice crystals which damage the membranes and significantly reduces the viability when you are thawing.

Hello 

Agree with researchers

And you can reducing the concentration of FBS to 2% in a highly consistent formula produced under cGMP conditions helps reduce the variability typically introduced by the 10–20% FBS used in classical media. There also are many unknown elements in FBS, such as signaling molecules, apoptotic factors, and nutrients. The variable concentrations of these components can cause lot-to-lot variation, which means that some FBS lots do not support MSC culture. When used to recover cryopreserved MSCs, our MSC-Qualified FBS . you can be replaced using MesenPRO RS™ Medium . it is helps improve expansion of MSCs compared with classical media (DMEM + 10% FBS)

Good Luck

Hi all, 

Thanks so much for your answers which I found of much useful now. 

It seems to me that the prevention of ice crystal and the post-freezing survival are important for the cryogenic cell storage. So, the use of DMSO for the former reason and FBS for the latter reason make sense to me now. 

I just have one thing to think about: FBS is expensive and minimizing its use may save cost. For example, Alexei said that some peole use 50% FBS + 40% Media + 10% DMSO which is still working well. Or in another answer, Jeanne used 40% PRP + 50 % Media + 10% DMSO.  So, in my case, I can use 40% FBS + 50% media (with 10% FBS) + 10% DMSO.  This should be working well. 

Hi Long Pham as per your last comment in the thread, you are right about the use of DMSO and FBS but then again about the composition of freezing media, Kosheeka would like to point out something:

In case of 100ml of 50% FBS + 40% Media + 10% composition, FBS is 50ml and media is 40ml. Whereas in case of 100ml of 40% FBS + 50% media (with 10% FBS) + 10% DMSO composition, FBS is 45ml (if we take the 10% FBS in media) and media is 45ml. So, it is only by optimizing that you can reach a proper conclusion regarding which composition will be suitable for your cells.