Super Absorbent Lower-Layers of Sanitary Pads: A Challenge in Sexual Aggression Cases
The lower superabsorbent layers in sanitary pads are a challenge for semen detection and DNA profiling. The protocols currently used for these samples consist on analysing only the upper layers. However, due to the sanitary pads’ aim, their composition and structure (1, 2) is designed in such a way that fluids and cells will be repelled by the hydrophobic upper layers and become enmesh within the SAPs’ hydrogel in the absorbent core (1, 3, 4). This suggests a loss of biological information, which may lead to an inaccurate genetic profile of the aggressor, since sexual aggression biological samples are usually mixtures of victim’s and aggressor’s bodily fluids with a higher concentration of the female fluids. Therefore, there is a need to improve the method of bodily fluids extraction from sanitary pads, taking into account the lower layers. Camarena et al (2017) recently referred a positive impact from cutting the pads and filtering with a nylon mesh (4) and an incubation with different chemical buffers, as isopropanol, was successful when extracting urine fluid (5). Furthermore, Carson et al (2013) presented the idea of pressure to help liberating fluids from the SAPs mesh (6). Our aim was to combine different chemical and physical treatments to optimize the maximum semen fluid out of the complex layout of superabsorbent pads, allowing the correct fluid diagnosis and consequently DNA quantity and quality for the posterior adequate genetic profiling.