DNA extraction from formalin fixed tissue using an alternative protocol

It is always a challenging task for obtaining desired amount of amplifiable DNA from formalin-fixed and non-paraffin-embedded tissue sample for the purpose of human individualization, since formalin fixation of tissue samples causes fragmentation of the DNA and formation of cross-linked protein-DNA complexes. The present study sought an alternative novel, simple but effective DNA extraction procedure from formalin fixed tissue sample that can produce a high-quality amplifiable DNA. DNA was extracted from a formalin fixed 12 weeks old abortedfetus sample using an alternative protocol. Quality of extracted DNA was subsequently tested through genotyping experiment using 23 microsatellite markers. A complete genetic profile was obtained using automated ABI Genetic Analyzer 3500xl. Quantity of DNA extracted from the formalin fixed tissue sample was found to be 23ng/il. This method produced a 100% amplification success rate for 23STR loci. The complete genetic profile was further successfully compared with the allegedfather and mother of the fetus for conclusive identification. The results suggested that DNA extracted using this novel method is likely to be suitable for genetic studies involving formalin fixed samples frequently received in the forensic laboratories in cases related to product of conception, abandoned babies, microtomized and stained histo-pathological slides etc. needing DNA test.