A simple apparatus for controlled pressure perfusion fixation.

An apparatus is described for vascular perfusion of small animals with fixative solutions which while simple and inexpensive allows quantitative and reproducible pressure control. Direct measurement of outflow pressure demonstrated that a sphygmomanometer used to supply external pressure to a plastic blood transfer pack achieved these features. Reproducibility of pressure was maintained by filling the bag with air between perfusions, or when smaller volumes of fixative solution were needed. Rodent brains from fetal to adult ages, and other animals of similar size, have been reliably well fixed by this method.