Do you know if any harm can be done to some chemicals of peptides or proteins if they will be stored in a regular freezer, like one people are byuing for their homes?
The only issue is the thermostatic switch . On domestic fridges these can cause sparks and so are dangerous if storing solvents. In our lab we remove these and wire in a new external switch. However, if you do not intend to store flammable solvents it should be OK.
Are you sure household freezer can reach -20 degree C, if your samples require that temperature to maintain its integrity, you need to consider if the household freezer can reach -20 degree C, otherwise no problem!
it is a question of stability of the temperature. some home refrigerators are better than others. but ti\e answer to your question is based upon how sensitive are your compounds to slight and moderate temperature changes that can last for a longer period of time then would exist in a scientific refrigerator.
In agreement with Wayne Morris answer writen above, avoid frost-free freezer- refrigerator, because they change temperature all the time for defrosting which damages samples, enzymes, etc.
The only issue is the thermostatic switch . On domestic fridges these can cause sparks and so are dangerous if storing solvents. In our lab we remove these and wire in a new external switch. However, if you do not intend to store flammable solvents it should be OK.
So, in conclusion, you don't want a self-defrosting freezer as per the above comments. If you can find a freezer without the defrost option on the domestic appliance market, then it could work if it gets cold enough, as long as you don't put solvents or solvent-wet peptides inside it.
Of course, if you have a departmental electrician who can move the parts that spark to the outside for you, and the freezer gets cold enough, then you are fine to work with solvents and peptides. If you are experienced, you can do this electrical work yourself, too, but that is a bigger and bigger "if" these days. Good luck, and yes, scientific equipment is overpriced.