A few ideas: first, figure out a way to obtain mites for practice , if
possible--prpeparing whole mounts of anything is an artsy-craftsy skill which
takes a lot of practice and fiddling around until you get a protocol worked
out. Second, if mites haven't been collected in 70% ETOH, they need to be.
Initially, they need to be cleared in 10% KOH; how long depends on the size of
the mite. Most mites won't require more than a few minutes, and if room
temperature KOH doesn't do the trick, warming it GENTLY will help. After
they're cleared, take them through a graded series of alcohols (back into 70%,
then 80, 95 and then 100%, each for an hour or so). If they're not cleared
adequately from the KOH, clove oil is an excellent clearing agent. Once
they've been through alcohol, you have a couple of options for mounting
medium--Euperal and Kleermount. Euperal is quite $$, but it is worth it for
unusual specimens for which you want to make good slides. Kleermount is
cheaper and is good for most routine stuff, such as preparing slides for
student teaching sets. If you use Euperal, you can take specimens directly
from 100% ETOH into it; if you use Kleermount, you must first take the
specimens through a xylene series (75/25 xylene/absolute alcohol, then 50/50,
then 25/75, then 100% xylene). For either mounting medium, put a drop of the
medium on a coverslip, add your mites using a fine wire probe, then quickly
invert the coverslip and place on a slide. Gently press on the coverslip to
distribute the medium under the coverslip and eliminate air bubbles.
An excellent reference, if you can find it, is "The Collection and Preservation
of Animal Parasites" by Pritchard and Kruse, 1982, University of Nebraska press
(I ordered my copy from BioQuip, an entomology supply outfit in California).
Good luck and contact me if I can offer any other suggestions!
Dr. Bob Garrison