To see uric acid (actually monosodium urate) crystals in tissue, the best thing to do is pick them out of the wet tissue with a needle, put them on a slide in a drop of water with a coverslip, and examine them promptly with polarization.
If they can't be seen on gross examination, then the special processing techniques mentioned certainly help, though often MSU will come through in routine processing. The real problem is for the pathologist. Most of the small-hospital pathologists I work with aren't allowed to have a polarizer on their microscopes, so they have to take the trouble to go to the urine scope (no, the broken-sunglasses shtick doesn't work), if they're allowed in the urine lab which they sometimes aren't. And if they're willing to take the time. To identify MSU, you need to demonstrate negative birefringence. That requires a full wave plate system (sometimes called a first order plate), and somebody has to have preserved the documentation so that the microscopist knows which way is up. In the absence of a procedure manual, the pee scope can be quite frustrating. (Also I have to spend five minutes cleaning and aligning it.) I'm not telling you anything I don't have to put up with at least once a month. Bob Richmond Samurai Pathologist Knoxville TN _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet