Cardiac Perfusion versus Immersion Fixation for the Production of Artifact-Free Brain Sections.

摘要

The postmortem chemical fixation of brain routinely results in some degree of artifactual tissue changes which are difficult to differentiate from preexisting pathology. More specifically, by light microscopy of hematoxylin and eosin-stained sections, hyperchromatic, purple neurons are frequently seen in completely normal brains. Preexisting early neuronal degeneration, however, may result in similar staining characteristics. Thus, a fixation technique which minimizes the occurrence of these dark neurons and other artifacts would be beneficial in the interpretation of subtle brain pathology. This study was conducted to evaluate and compare several methods of tissue fixation to determine which technique produced the most artifact-free brain tissues. Rats in 9 groups of 10 each were euthanatized and their brains immediately fixed by intravascular perfusion or immersion in neutral buffered formalin (NBF) or Karnovsky's in Locke's buffer (KLB). (jes)