Primer: tissue fixation and preservation for optimal molecular analysis of urologic tissues.

Appreciation of the different methods of tissue handling is a prerequisite to obtaining accurate and biologically relevant tissue-based information. When a tissue sample is removed from its environment, biological changes are induced within its constituent cell population. It is inevitable that artefacts will be induced through obtaining and processing tissues, irrespective of whether the samples comprise a few cells derived by fine-needle aspiration or larger specimens obtained surgically.