1) If nail clippings are infected with a fungus, the DNA of the individual and of the fungus should both be present and receive the signals, as far as I know.
I think fresh nails are always best, but I do not have an answer as to whether nails may be frozen or how long they would last if frozen.
2) Polish doesn't contain DNA, so should be no problem.
As far as I know, the remover doesn't have DNA - and isn't going to take the DNA out of the nail, so should be OK as well.
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