Optimising silica-based solid phase DNA extraction methods for low concentration forensic samples

Trace DNA analysis from minute biological samples has become commonplace in modern forensic laboratories due to increased sensitivities in genotyping systems and improved extraction chemistries. However, analysis still remains a challenge as no single protocol exists that will isolate DNA in both sufficient quantity and quality for downstream applications. Extraction is the most crucial step for maximising recovery of DNA, and thorough optimisation of procedures is needed to ensure informative genetic profiles can be generated. This review will investigate the efficiency of different methods available for isolating trace quantities of DNA from forensic samples, discussing their advantages and limitations. It will explore improvements to the extraction methodology, including optimisation of the elution volume and methods of post-extraction purification. Lastly, centrifugal filters will be debated for their concentrating properties and ability to improve the recovery of trace DNA.