MSB Trading - 2020, page-8628

Hi there, this is my first post on Hotcopper, and I'm still a newbie when it comes to investing and trading, but as someone who works in the Biotech industry, and regularly performs cell culture, I think I can answer your question about storage of cells. The short answer to your question is yes, cells can be frozen down (either at -80 degrees C or in liquid nitrogen) provided the cells are suspended in what we call freezing media, which is a mixture of fetal calf serum (FCS) and 10% DMSO (a cryoprotectant). This helps prevent the cells from being damaged by ice crystal induced mechanical injury.

How long do the cells remain stable? It depends on whether you freeze the cells at -80 degrees C, or in liquid nitrogen. Generally speaking, cells stored at -80 degrees cannot be recovered after 6 months. However, cells can be stored indefinitely in liquid nitrogen. I've personally recovered cells from a liquid nitrogen that had been frozen down for over 20 years, and they were fine. Once the cells are thawed out they have to be placed in culture media immediately to prevent the cells from starving.

For injection into a patient, this is where things get tricky. The cells have to be taken out of culture and re-suspended into a saline solution (usually PBS). However cells will not remain viable in a saline solution for long, and even at 4 degrees C, cells will start to die off after as little as half an hour. Its possible that Mesoblast may have found a way to extend this time with some additives to the saline solution, but generally speaking you need to be quick with this stage of the process, as this is when the cells are most at risk.

Hopefully that clears some things up. Let me know if you have any more questions, I'll be happy to give what little knowledge I have.