>You can get over 180 proof by distilling it yourself, but it might be
>difficult convincing the police that your still is for scientific research.
Everclear is 95% alcohol, the highest concentration of ethanol obtainable by
simple distillation. Absolute (100%) alcohol may be obtained by adding benzene
to 95% alcohol & distilling that mixture. But you don't want to mess around
with benzene.
People who work with DNA usually recommend storage of specimens in 95%
alcohol. As mentioned, changing the solution once within a few days is a good
idea in any situation, unless the volume of preservative is much larger than
that of the specimen.
A.