DNA isolation and amplification from formaldehyde-fixed animal tissues rich in mucopolysaccharides, pigments, and...

Formaldehyde, once the fixative of choice, is a known obstacle to DNA extraction and amplification. However, when fixed tissues contain other problematic compounds such as pigments, mucopolysaccharides, and chitin, and when only small amounts of archival tissues are available, obtaining amplifiable DNA can become extremely challenging. Here, I present a procedure that has enabled me to extract amplifiable DNA from minute specimens of polychaetes successfully; like many other invertebrates, these worms are rich in pigments, mucopolysaccharides, and chitin. This inexpensive procedure can be used to obtain and amplify DNA from miniscule amounts of other similarly-problematic formaldehyde-fixed tissues as well.