Cross-linking characteristics of biological tissues fixed with monofunctional or multifunctional epoxy compounds.

The cross-linking characteristics of biological tissues fixed by various epoxy compounds with different chemical structures (i.e. number of epoxide functional groups and backbone length) were investigated. Generally speaking, the tissues fixed with monofunctional fixatives were more pliable than those fixed with multifunctional fixatives. The fixation indices of the fixed tissues did not seem to be affected by the chemical structures of the fixatives. However, the number of functional groups and backbone length of the fixatives did play an important role in influencing the denaturation temperatures of the fixed tissues. In general, the denaturation temperatures of the multifunctional fixed tissues were higher than those of the monofunctional fixed tissues. Among the monofunctional fixed tissues, it was found that increasing the backbone length of the fixative decreased the denaturation temperature of the fixed tissue. This effect was present until the backbone length of the fixative became large enough.