Temperature effect of protein? - (Aug/09/2007 )

I would like to know if there is any difference in temperature effect on protein between
-80 degree C and -20 degree??

any one has any idea what effect low- temperature has on protein???

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you mean for long-term storage?

it depends on the protein; some Ab should not be freezed at -80°C but at -20°C as the freezing buffer becomes not solid/crystal at -20°C;
if you can freeze solid, more important is the freeze protocol; shock freezing with dry ice or liquid N2 is to recommend; storage at -80 is then to prefer

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There's only one safe way to see if your protein is going to be happy at -20 or -80: try it. Sorry.
If you have to freeze, consider adding an excipient. If you have to keep the protein pure, you can add a sugar such as trehalose, otherwise a bit of BSA acts as a good cryoprotectant.

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hi

i was refering for long term storage.
we were planning a stability study, so i wanted to get an idea will there be any change with -20 and -80, if there is no basis for any change i may not carry out -80..thts why needed ur advice

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OK, what length of time are you thinking about when you say a stability study? 1 month? 1 Year? Is there any data on the Web or in PubMed for your protein? If not, you are just going to have to do the experiment!

If you are doing a study, you are still going to have to try both. I can't say if your protein will be happy, because I don't know what protein you are using, and different proteins act differently.

Prepare a number of vials of the protein, put them into the respective freezer (-20 and -80), and test at a number of time points (say 1 week, 2 weeks, 1 month, 2 months). Sometimes there is simply no alternative to doing the experiment, that's why we are called experimentalists, rather than theorists.

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We make many aliquots of our protien and the unsed aliquots loses activity just being in -80C after a few weeks.

Some others donot lose activity but it varies.

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