I work in a biorepository and I was wondering as to why certain specimens are stored at certain temperatures. We have storage of +4c refrigerator, -20c freezer, -80c freezer, and LN2 storage. I know why some material is stored in the LN2 tanks, but why is some material stored in +4c, -20c, -80C freezers? We store all types of material from plasma, serum, drug material, cells, and anything else you can think of that a researcher might need stored.

I would appreciate the help to understand more and pass it along to my coworkers... curious minds want to know.

Sorry. I don't know the answer to this. Isn't there a boss who knows why you follow the protocols you follow? Or a manual for the company?

I know I once froze some butterfly eggs for two weeks, by accident, found them, thawed them and they hatched...

Maybe it has to do with whether you have whole cells or not.

Which things are stored at which temperatures?

We just place their material (samples) in whatever temp freezer that they want. All that we do is store their material for a time; we do not decide at what temp certain material should be stored at.

Different things are stored at various temps for different reasons. Be a little more specific.

We store blood, serum, plasma, vaccines, cell lines and anything that a scientist might want to preserve for his study or clinical trial.

This explains some basics.

Cryobiology - Wikipedia, the free encyclopedia