Autolysis, known as tissue decay, begins immediately after tissue is removed from the body and mainly affects DNA and RNA. If molecular profiling is a consideration for a tissue specimen, careful planning before the procedure is essential to ensure that tissue will be collected, transported, and handled in a manner that will maximally preserve DNA and RNA.
There are three significant considerations during initial tissue handling to minimize damage to DNA and RNA. Variables such as temperature, time of handling, and specimen size affect the decay rate and should be managed to minimize damage.
Special fixatives may be used to protect tissue morphology for histologic examination and preserve the molecular properties simultaneously. As molecular testing methods evolve, it may become necessary and more commonplace for "universal" fixatives (those that work well for both routine histology and molecular testing) to become part of routine tissue handling in clinical histopathology.
