The Preservation of the Zoological CollectionsStaff: Julian Carter
Amgueddfa Cymru - National Museum Wales is one of the few museums in Europe with expertise in museum conservation covering the natural sciences. The zoological collections cover a wide range of materials which includes fluid preserved specimens, insects, dried shells and taxidermy mounts. Many factors can affect the long term preservation of these collections. This includes poor environmental conditions such as incorrect temperatures and humidity, poor storage and preservation, and insect pest infestation.
One of the most important methods of preserving zoological specimens is the use of fluid preservation. The use of ethanol and formaldehyde based solutions have been in use for over a century. They have the advantage of enabling the whole specimen to be preserved including both external shape and internal morphology. However there are problems with these methods such as shrinkage, colour loss and chemical changes. In addition the collections are increasingly used in molecular studies which require the preservation of DNA. Our ongoing research has been looking at some of these issues.
We are currently exploring the relationship between the pH of the preserving fluid (80% ethanol in deionised water) and its effect on biological tissue. A series of tissue samples have been preserved at a range of pH levels from pH3 to pH13. The pH levels have then been monitored over a 6 month period. The samples and the preserving fluid have then been analysed using a range of methods including Fourier Transformed Infra Red (FTIR) spectrometry, protein assay and DNA extraction. The results should help improve our understanding of fluid-preservation chemistry.