Dimethyl sulfoxide (DMSO) is a widely employed cryoprotective agent in the field of cryopreservation due to its ability to mitigate the detrimental effects of ice crystal formation, which can inflict harm upon cells during the freezing process. Nevertheless, it should be noted that elevated concentrations of DMSO can induce cytotoxicity in cells. The introduction of cryoprotective media prior to the addition of dimethyl sulfoxide (DMSO) serves to expose cells to a lower concentration of DMSO initially. This approach mitigates the potential for cellular damage and facilitates a controlled modulation of DMSO concentration.

thank you Swaraj Kumar Babu sir.

Hello Yukti Kataria

How do you prepare the freezing medium?

DMSO is toxic to cells if the cells are exposed to DMSO for prolonged periods (e.g. 10% DMSO for several hours at room temperature) because heat is generated when DMSO is dissolved in aqueous solution. So, it cannot be added directly to the cells.

DMSO must be diluted to, for instance, 20% in cell culture medium, allowed to cool below 37°C and subsequently added to the cells to a final concentration of 10%.

We first prepare the freezing medium containing 90% culture media +10% DMSO and place it on ice, and then resuspend the cell pellet which we have obtained after centrifugation of the cell suspension in 1 mL of freezing medium per cryovial.

Best.

Thanks a lot for your valuable response. We use 7.5% DMSO in 92.5% media. Best regards

Swaraj Kumar Babu answer is correct, in addition, the hydration of DMSO when it dissolves in water liberates heat and this could raise the temperature, depending upon the starting point, over 370C. DMSO at high concentrations can denature proteins, and dissolve lipids, therefore it is best to try not to expose cells to great than >10% DMSO, even during local mixing if at all possible.

Thanks Philip G Penketh sir for your valuable response.