"Reagent" alcohol is ethyl alcohol that the American Chemical Society deems suitable for organic synthesis.  It may or may not be suitable for histology.  Unless it has a tax stamp on it, it is not pure.  Reagent alcohol is often denatured with methyl isobutyl ketone which may create problems; sometimes it is denatured with kerosene which always creates problems in histology.

I use ethyl alcohol sold for histological purposes.  It has usually been denatured with methanol which never causes problems in histology.  Rarely, it is denatured with brucine, which didn't cause me any trouble.

Tax-stamped alcohol is great if you can afford it or work at an institution that can get it tax-free.

Allen A. Smith, Ph.D.
Barry University
School of Graduate Medical Sciences
    Podiatric Medicine and Surgery
Miami Shores, Florida  33161-6695