Thermal Analysis of Paraffin-Embedded Tissue Blocks for Anatomic Pathology Processes

Area of Science:

• Biomedical Engineering
• Materials Science
• Anatomic Pathology

Background:

• Accurate diagnosis in anatomic pathology relies on optimal tissue sample preparation.
• Temperature fluctuations can compromise tissue integrity and diagnostic accuracy.
• Current refrigeration methods lack standardized protocols for temperature control.

Purpose of the Study:

• To determine the most efficient refrigeration method for anatomic pathology samples.
• To predict the time window for optimal tissue sectioning before thermal degradation.
• To analyze thermal stresses during cooling and heating transients.

Main Methods:

• Thermal finite element (FE) analysis using comsolmultiphysics.
• Validation of FE simulations with thermocouple-based measurements on various tissues (muscle, bone, fat).
• Evaluation of three cooling methods: cold plate, cooled environment, and forced convection.

Main Results:

• Forced convection at -20°C with 5 m/s airflow achieved the shortest cooling time.
• Thermal stresses can be modulated by adjusting airflow speed.
• The time available for optimal sectioning after refrigeration ranged from 12 to 310 seconds.

Conclusions:

• Forced convection is the most efficient refrigeration method for paraffin-embedded tissue samples.
• Quantified cooling and optimal sectioning time windows aid in process optimization.
• Understanding thermal stresses is key to preventing sample damage during processing.