An alternative way to stain the gel in gel electrophoresis without causing contamination

Gel electrophoresis is an important invention that can help us separate molecules based on size and charge. It has been used in many circumstances, including analysing the DNA sequence during forensic investigations and obviously, in many disciplines regarding microbiology and biological sciences as a whole. The biggest headache that comes with gel electrophoresis is the part that requires staining of a gel. Very often, if not well done, it will cause contamination and splash. In this poster, we talked about a different way to stain the gel used in gel electrophoresis without causing too much contamination

Age and sex estimation using fractal analysis in Brazilian adults: a discriminant analysis

This study assessed the accuracy of fractal analysis (FA) to estimate chronological age and sex in Brazilian adults for forensic investigations. The gender-balanced sample comprised lateral cephalometric radiographs of 120 individuals, stratified according to age (20-29, 30-39, 40-49, 50-59 years) and sex (female and male). A trained calibrated examiner measured the fractal dimension (FD) of the mandibular ramus and mandibular angle. Linear regression and multiple logistic discriminant analysis were carried out to explore the accuracy of FA. For all analyses, p-values < .05 indicated statistical significance. Overall, mean FD values were 1.49±0.10 for the mandibular ramus and 1.48±0.09 for mandibular angle. Results were more accurate in males than females for discriminating age and sex. The multiple discriminant analysis indicated that FA distinguished sex in 61.7% males and 58.3% females. In addition, the mean difference between actual and predicted value was 9.5 years and 10.1 years for men and women, respectively. Fractal analysis accurately identified sex- and age-related differences in the trabecular pattern of the mandible of Brazilian adults, confirming its utility for forensic investigations. Further studies investigating other populations are needed to assess the accuracy of FA for Forensic Dentistry.

The assessment of the efficacy of STRs panels recommended by the ISAG for canine pedigrees analysis for forensic casework

Canine DNA is widely used in forensic investigations, particularly in dog attacks cases on humans. Nowadays, STR markers are employed worldwide in forensic laboratories to test human and animal genotypes. In the study we analysed the effectiveness of panel – 18 STR as previously recommended by ISAG and the same panel with three additional markers – 21 STR, which has been recommended by ISAG as the core panel for dog identification since 2016. We calculated the PD, PID for these sets of panels and estimated RMP based on the DNA profile obtained during an investigation of a woman bitten by a dog. The high combined CPD value for 18 and 21 STRs showed values close to 1.0. The CPID value for theses panels was 5.2 × 10−10 to 6.4 × 10−14. Statistical analysis estimated the random DNA match, in the case of the woman bitten by a dog, with a probability of 4.3×1019 and 2.8×1022, using 18 and 21 STR panels respectively, and that the canine DNA profile from the crime scene originated from the suspected dog and not from another random dog. Our results show that both STR panels can be used effectively for individual identification and forensic casework.