Avian DNA extraction: An economical and efficient alternative for Farmer-fixed samples

Cytogenetics laboratories often accumulate vast collections of cells fixed in Farmer’s solution (3 parts methanol to 1-part glacial acetic acid), stored long-term in freezers. While many of these samples are unsuitable for conventional cytogenetic analyses, they hold potential for molecular applications, especially as ethical restrictions around the collection of biological material through invasive procedures (e.g., biopsies, tissue excision, bone marrow aspiration) become increasingly stringent. However, extracting DNA from these cells presents significant challenges, such as structural fragility induced by the fixative and potential genetic material degradation, which can compromise subsequent analyses, including PCR. This study developed and standardized a protocol for extracting DNA from Farmer-fixed avian cells using accessible and low-cost reagents. The method proved economical and efficient, even for decades-old samples, recovering DNA suitable for cytogenomic and molecular studies. This approach significantly advances sustainable practices in science by utilizing long-stored samples that might otherwise be discarded, this approach provides a cost-effective strategy that reduces the need for new collections and aligns with current ethical guidelines in molecular genetics research. Compared to commercial kits, the protocol demonstrated economic viability while expanding the use of biological collections in genetic research and evolutionary studies.