Experimental Evaluation of Dehydration and Rehydration Methods in Formalin-Fixed Tissues for Anatomical Studies
Medical Degree Final Thesis (TFG) — Universidad de Las Palmas de Gran Canaria
Objective. Experimental study evaluating alternative dehydration and rehydration methods for the preservation of cadaveric tissues used in anatomical studies, focusing on macroscopic morphology and reducing reliance on toxic formaldehyde.
Methods. Animal and human tissue samples from the tissue bank of the Department of Human Anatomy and Embryology (ULPGC), initially preserved in 4% formaldehyde or ethanol–acetic acid–glycerin (EAG) solution, were dehydrated using three approaches: immersion in 96% ethanol, sodium chloride, and refrigeration at 4 °C. Rehydration was performed with distilled water or 5% Tris-buffered saline (TBS, pH 8.8). Macroscopic changes in volume, texture, color, and structural integrity were photographically documented at pre-dehydration, post-dehydration, and post-rehydration stages.
Key findings. Dehydration with 96% ethanol preserved tissue structure most effectively, with minimal shrinkage and improved translucency after TBS rehydration—particularly in small intestine and fetal limb samples. Sodium chloride dehydration produced superficial salt deposits that affected aesthetic quality but allowed comparable rehydration. Refrigeration caused marked shrinkage and stiffness with limited recovery, especially in large formaldehyde-fixed specimens (e.g., human kidneys, fetal cat), likely due to protein cross-linking. TBS outperformed distilled water in restoring volume and natural color, attributed to better osmotic balance. Naturally dehydrated samples (e.g., sun-exposed lizard) also showed significant recovery with TBS.
Conclusion. The combination of 96% ethanol dehydration followed by TBS rehydration emerges as a promising alternative for anatomical preservation, supporting reduced dependence on formaldehyde for fixed specimens. Limitations include fungal contamination in some samples and the absence of microscopic analysis. Future work should incorporate histological and ultrastructural evaluation and explore additional rehydration solutions across tissue types.
More projects coming soon
Additional clinical, research, or academic projects will be listed here as they become available.