How do I choose the right mounting media for my sample?

A good mounting medium should meet the following criteria: 

• Have a refractive index (RI) as close as possible to that of fixed tissue (approximately 1.53)
• Be colorless and transparent
• Harden relatively quickly
• Have a dry to non-stick consistency
• Not cause stain to diffuse or fade
• Should set without cracking, shrinking, crystallizing, or otherwise distort the material being mounted
• Have no adverse effect on tissue components
• Be able to completely permeate and fill tissue interstices
• Be resistant to contamination, particularly growth of microorganisms
• Be completely miscible with clearing or dehydrating agent
• Should not shrink back from the edge of cover glass
• Should not leach, react with, or induce fading in stains or reaction products 
• Should protect the section from oxidation, changes in pH and other physical or chemical damage
• Should remain stable once set