Restoration and Preservation of Pathological Surgical Specimens

San Francisco State University received a historically significant pathology specimen collection from Stanford University in the 1970s. Originally, the specimens had been preserved in formaldehyde and water, but as the years went by the formaldehyde degenerated, causing decomposition of the tissues. As a result, the anatomy lab had stopped using them as teaching tools because they had become cloudy and dark. Ethanol has become the widely accepted professional method of liquid preservation partly because it is a less toxic and more environmentally friendly solution for long‐term storage and display. However, not much has been written about its use for human tissue revitalization in collections such as this. We found that the tissues dried out significantly when we changed solvents immediately from formaldehyde and water to an ethanol solution. After researching the problem, we decided to use sequential positive step‐gradient incubation in alcohol. First, the specimens were drained of the formaldehyde and water. Then, the ethanol was introduced in 20% increments. The slow steps of the ethanol incubation prevented the tissue from drying. Four months after this revitalization, the results show that the tissues have not shrunk and have sustained their integrity. By restoring these rare specimens to prime condition, we are once again able to use them as invaluable learning tools in the anatomy lab. Grant Funding Source : San Francisco State University Biology Department