Whole animal perfusion fixation for rodents

Area of Science:

• Neuroscience
• Histology
• Biomedical Engineering

Background:

• Immersion fixation is challenging for large tissues like the brain, leading to delayed preservation and cellular changes due to hypoxia.
• Effective tissue fixation requires rapid and uniform delivery of fixatives to all cellular components.
• Existing perfusion fixation methods may not optimally utilize the vascular network or match physiological pressures.

Purpose of the Study:

• To describe a low-cost, rapid, and uniform perfusion fixation technique for rat brains.
• To optimize tissue preservation for subsequent immunohistochemistry.
• To demonstrate an effective method for utilizing the vascular system for fixative delivery.

Main Methods:

• Perfusing 4% paraformaldehyde through the vascular system of rats via cardiac puncture.
• Matching physiological pressures during perfusion for optimal fixative distribution.
• Utilizing the natural vascular network for rapid and uniform delivery of the fixative.

Main Results:

• Achieved rapid and uniform fixation of the entire rat brain.
• Preserved tissue in a life-like state, suitable for immunohistochemistry.
• Demonstrated superior utilization of the circulatory system compared to gravity-fed methods.

Conclusions:

• Vascular perfusion fixation is a superior method for preserving large tissues like the brain.
• This technique provides high-quality, uniform preservation essential for advanced molecular and cellular analyses.
• The described method offers a cost-effective and efficient approach to tissue fixation.