Can DNA Barcode Study be Done from a Museum Specimen Fixed in a Formaldehyde Solution? A Case of Emys orbicularis (Linnaeus, 1758)

Abstract

DNA barcoding, a molecular taxonomy technique, has been increasingly used by herptile taxonomists in recent years. In DNA barcoding studies with museum specimens, there are difficulties in achieving success in specimens that have been exposed to formaldehyde, which is usually used as a fixative, for a long time and intensively. Here we studied the effect of formaldehyde on the application of the DNA barcode method in Emys orbicularis specimens stored in 4% formaldehyde and 70% ethanol solution since 2008 and 2014. Sanger sequence analysis of tissues taken from samples stored in both ethanol and formaldehyde solution successfully yielded sequences of 623 bp. In conclusion, the use of ethanol solutions should be preferred for mid or long-term sample storage, especially in the context of molecular studies. In cases where the use of formaldehyde is unavoidable, it may be advisable to use extremely low concentrations to increase success in molecular research.