For demonstrating monosodium urate in tissues, polarization microscopy using
a first order plate (full wave plate) is essential, and is best done on bits
of crystalline material picked out of the gross specimen and spread out in
water on a slide.

The usual medical problem is distinguishing monosodium urate needles from
calcium pyrophosphate rectangular crystals. The first order plate examination
accomplishes this, though I always have to look it up in a book (for some
reason this information cannot be put in a procedure manual) to remember
whether it's port left starboard right or the other way round.

The pathologist's microscope usually doesn't have a polarizer, and the
pathologist must go use the pee lab scope to do the examination. (I doubt
this information is transmitted in the usual clinical pathology residency.)

Bob Richmond
Samurai Pathologist (and Army [rather than Navy] veteran)
Knoxville TN