Vasculature is rinsed with room temperature normal saline for 0.5
to 1.0 ml/gm body weight or until blood return from right heart
is substantially cleared. Some add heparin and/or vasodilators
such as nitrite to this rinse. This is usually not necessary in wellanesthetized
animal with rapid progression through steps 1 and 2
to prevent cessation of blood flow and intravascular coagulation.
For certain fixatives containing low percentages of paraformaldehyde
and/or glutaraldehyde and larger animals, it is possible to