A novel FTA™ elute card collection method that improves direct DNA amplification from bloodstained concrete

Concrete is a common construction material found in residential and commercial buildings, bridges and parking lots that is a composite matrix containing aggregate held together with cement. The porous nature of concrete can make the collection and genotyping of biological fluids, such as blood, challenging. Forensic evidence can become embedded within the matrix, potentially reducing the amount of DNA available for analysis. In forensic science, “direct” amplification refers to a genotyping method that amplifies a DNA profile directly from a sample without DNA extraction, saving time and money. We investigated a novel application of Whatman™ FTA™ Elute cards in their ability to directly amplify PowerPlex® Fusion and Y23 profiles from minute amounts of blood that had been deposited on different concrete structures. In comparison to traditional collection methods, directly profiling blood stained construction materials using FTA™ Elute cards increased the percentage loci amplified and significantly improved both allele peak height and peak height ratio while reducing allelic drop-out. FTA™ Elute cards can provide a reliable, inexpensive and superior alternative to traditional methods.