Civil War Field Hospital: STR Analysis of Samples Collected from a Bloody Surgical Table

During the last battle of the Civil War, the Hillsman House was used as a field hospital to treat hundreds of soldiers. In 2018, Jones and McClintock demonstrated the ability to profile aged bloodstains, by traveling to the Hillsman House and analyzing bloodstains found on the floorboards5. During their study, marks observed on the floor were presumed to be from the surgical table, however, the original table was no longer at the house. Since then, the original wooden surgical table was acquired and presumed bloodstains were visualized using an alternate light source (ALS) and collected via swabbing and scraping. The samples were subjected to the presumptive tests Phenolphthalein and Leucomalachite Green (LCG) to determine if blood was present in these samples. Next, the Qiagen DNeasy® Blood & Tissue Kit and Qiagen Investigator® Lyse & Spin Basket Kit were used as DNA extraction methods and later compared by quantification using the NanoDrop 2000TM spectrophotometer and the QuantStudioTM 5 Real-Time PCR system. The amplified samples were subjected to both gel and capillary electrophoresis using a 1.5% agarose gel and the AB 3500 Genetic Analyzer respectively. Finally, electropherograms were interpreted using the GeneMapperTM ID-X software. All presumptive tests yielded negative results. However, after extraction, each sample yielded a quantity of DNA, and no correlation between the quantity of DNA and the quality of DNA profile was observed. Samples yielded both partial and full profiles with varying qualities between samples, with increasing the injection time from 15s to 24s providing higher quality profiles. However, a downward slope, the presence of alleles in lower molecular weight loci, and overwhelming mixture profiles were not observed as expected for degraded DNA samples with multiple contributors. Additionally, this research showed the ineffectiveness of the Investigator® Lyse & Spin Kit for DNA extraction from a wooden substrate. Lastly, this study indicated the absence of a correlation between the quality of the DNA profile and the extraction/collection technique.