Most crimes committed are against property (theft, robbery) and against the person (bodily harm, sexual violence, murder), but very often the perpetrators are not punished, since traces with analyzable biological material that could identify them cannot be found. In Italy in the year 2000, 86.95% of crimes remained unpunished, a percentage that increases to 96.12% in the case of theft (1). Apart from the few cases in which crimes are planned and precautions are taken to prevent leaving any biological traces at the scene, in most crimes of this type, i.e., theft, robbery, bodily harm, etc., criminals do not wear gloves or other devices, and fingerprints are the only evidence available. The literature contains preliminary studies or case histories on the possibility of recovering DNA from fingerprints left on the skin or on rope, cord, wire, etc., used for strangling, on gloves, knives, solid parts of cars and other objects, and on the interference by substances used to highlight fingerprints during later genetic analysis (2,3). These works report isolated experiments dictated by the need to resolve definite cases. Systematic studies of various factors influencing the success of analysis, such as recovery techniques, interference by contaminants, i.e., latent fingerprint enhancers, and amplification protocols of low-copynumber (LCN) DNA usually recovered from fingerprints, are in progress (4-9). Systematic studies of the influence of various modes of contact and type of substrate in the success of PCR analysis have not been exhaustively carried out. Lastly, the relevance of contamination by different subjects due to secondary and tertiary transfers affecting the robustness of results and the usability of analytical results in court must all be considered more deeply. The same origin of the DNA found in these skin contact traces and the influences of individual and exogenous factors in the number of cells left with the fingerprint still remain unclear. Therefore, the use of this substrate for genetic identification is a subject of passionate debate in the forensic community, and further contributions are still necessary to highlight the advantages, difficulties and limitations of DNA analysis from fingerprints. This study was carried out with the aims of investigating the amount of DNA recovered from various substrates and the influence on it of individual and exogenous factors, as well as the suitability of DNA recovered from fingerprints for personal identification by DNA microsatellites. The importance of contamination by exogenous DNA transfer and the stochastic effects on analysis from sampling minimal amounts of DNA recovered from fingerprints were also considered. Materials and Methods Collection of Samples The fingerprints from eleven persons working in the laboratory were applied to the following clean substrates: glass, metal (alloy metallic surfaces), and wood (cortex of hard wood). Experiments were carried out without washing the hands and immediately after

Deep knowledge of the genetic features of SARS-CoV-2 is essential to track the ongoing pandemic through different geographical areas and to design and develop early diagnostic procedures, therapeutic strategies, public health interventions, and vaccines. We describe protocols and first results of the Ion AmpliSeq™ SARS-CoV-2 Research Panel by a massively parallel sequencing (MPS) assay. The panel allows for targeted sequencing by overlapping amplicons, thereby providing specific, accurate, and high throughput analysis. A modified reverse transcription reaction, which consists of the use of a SARS-CoV-2 specific primers pool from the Ion AmpliSeq SARS-CoV-2 Research Panel, was assessed in order to promote viral RNA specific reverse transcription. The aim of this study was to evaluate the effectiveness of the Ion AmpliSeq™ SARS-CoV-2 Research Panel in sequencing the entire viral genome in different samples. SARS-CoV-2 sequence data were obtained from ten viral isolates and one nasopharyngeal swab from different patients. The ten isolate samples amplified with 12 PCR cycles displayed high mean depth values compared to those of the two isolates amplified with 20 PCR cycles. High mean depth values were also obtained for the nasopharyngeal swab processed by use of a target-specific reverse transcription. The relative depth of coverage (rDoC) analysis showed that when 12 PCR cycles were used, all target regions were amplified with high sequencing coverage, while in libraries amplified at 20 cycles, a poor uniformity of amplification, with absent or low coverage of many target regions, was observed. Our results show that the Ion AmpliSeq SARS-CoV-2 Research Panel can achieve rapid and high throughput SARS-CoV-2 whole genome sequencing from 10 ng of DNA-free viral RNA from isolates and from 1 ng of DNA-free viral RNA from a nasopharyngeal swab using 12 PCR cycles for library amplification. The modified RT-PCR protocol yielded superior results on the nasopharyngeal swab compared to the reverse transcription reaction set up according to the manufacturer’s instructions.

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