I'm just wondering what is an appropriate temperature to store a isolated protein. Is it 4 oC or -20, -80 oC or liquid nitrogen? Some experts suggest that proteins should always stored in 4 oC.
Usually proteins could be effectively stored at 4C but using temperature of - 20-40 C , proteins can be stored for a much longer time...Here is an interesting PDF..
Allowing the protein to freeze naturally will cause ice crystal to form that can disrupt protein structure. When frozen in N2, the process is so fast, no ice crystals have time to form, effectively freezing the protein in a protective cryo-sleep for use later.
My experience is protein can effectively stored at 4 degree Celsius for at least 2 years.
I figured out that a certain kind of protein can be stored in the temp of 4 degrees as a limit while an appropriate container also takes part of it. A few catalysts can also help the containment of it.
Yes, isolated proteins can be stored at various temperatures depending on the protein's stability and the storage duration. Here are some general guidelines I got:
Zero°C (refrigerator): Short-term storage of a few days can often be done at 4°C (refrigerator temperature), but this is not ideal for long-term storage as proteins can degrade over time.
minus 20°C: Many proteins can be stored for a longer period at -20°C. However, multiple freeze-thaw cycles should be avoided, as they can lead to protein degradation.
minus 80°C: For long-term storage, -80°C is commonly used. Proteins can often be stored for several years at this temperature without significant activity loss.
Liquid Nitrogen (-196°C): Proteins can be stored in liquid nitrogen for ultra-long-term storage. This is often used for preserving biological samples like cells, but it can also be used for proteins. It’s important to note that the storage temperature must be kept permanently below -130°C to prevent ice crystal formation.
Remember, the stability of proteins can vary greatly, so these are general guidelines and might not apply to all proteins. It’s always a good idea to check the literature for specific storage conditions for your protein of interest. Also, the use of cryoprotective agents such as DMSO or glycerol can help reduce the risk of ice crystal formation, which can damage proteins.