Collecting and preparing mammal hairs for identification with optical microscopy

Hair microstructure is a useful tool to identify mammals and is applied in several disciplines such as forensic sciences, ecology, epidemiology, arqueology and paleontology. The methods applied to collect and prepare mammal hairs to identify them under the optical microscopy are many and range from the most cheap and rapid to the most expensive and laborious. The present study aims to test different methods to collect, clean and prepare mammal hairs for Cuticular and medullar patterns observation under optical microscopy, to compare these methods to the literature and to describe in detail a new suggested method. To prepare the reference collection, hairs were collected from the back of identified museum specimens with known collecting localities. Cuticular impressions were obtained pressing hairs against a thin nail varnish layer let dry for 15 to 20 minutes on glass slides. In order to observe the medullar pattern, hairs were submitted to diafanization with comercial oxigenated water 30 Volumes for 80 minutes. Permanent glass slides were mounted with Entellan and temporary ones with glicerin. The advantages of this method are the easy aquisition and handling of the material and the practical execution, enabling its use in the field.