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DNA isolation in sexual assault cases is complicated by the presence of large numbers of female epithelial cells, which are often in vast excess when compared to spermatozoa. The two-step differential extraction has been a standard method for isolating the spermatozoa; however, new techniques in forensic science allow the use of precision techniques for capturing spermatozoa. We have used an immuno-magnetic bead-based technique for sperm cell separation. We identified two antibodies that were specific to spermatozoa: SP17 polyclonal antibody and SP10 Intra Acrosomal Protein monoclonal antibody. These were conjugated to Dynabeads® M-450 Epoxy beads and used to isolate the spermatozoa in samples that exhibited the characteristic of sexual assault samples. Using these antibodies, we achieved separation of spermatozoa in the samples with sperm concentration 104/ml and 103/ml; STR analysis produced full male profiles. Mixed profiles were obtained with reduced levels of spermatozoa. Our preliminary data illustrate the potential to apply antibody-based capture to sexual assault cases.

The effectiveness of five methods for the preservation of bone were assessed: cell lysis solution (with 1% sodium azide), dehydration/freeze-drying, ethanol (96%), freezing, and room temperature storage. Preserved bone samples were extracted using five optimised extraction methods. These preservation methods were tested for their efficiency for storage of fresh and degraded bone samples for 6 weeks, 6 months and 1 year. Freezing was found to be the best preservation method for longer-term storage of bone samples; this was followed by ethanol (96%), dehydration/freeze-drying, and room temperature storage. Full profiles were obtained from bone samples using all these preservation methods.

Mitochondrial DNA analysis has earned its place in the field of genetics for providing a new window into understanding population ancestry. Its ability to produce results from minimal or decayed samples where nucleus DNA profiling proves are difficult is an additional benefit to forensic genetics. A total of 150 whole blood samples were collected on FTA paper, from Arabs population in United Arab Emirates, including inhabitants from rural regions. Both extraction of whole blood samples using PrepFiler® as well as direct amplification of mtDNA control region from purified 1.2 mm disc of FTA card stained with blood were attempted in this study. Quantity of the amplified control region was estimated using gel electrophoresis. Three sets of primers were used afterward to sequence purified products of amplified control region of mtDNA using Sanger sequencing method. 150 mtGenome sequences were obtained for UAE Arabs population, generated using MPS technology – Ion™ 5S. Concordance with control region sequences obtained using Sanger Sequencing approach was investigated. Resulted haplotypes were compared against worldwide mtDNA database (EMPOP) and estimated haplotypes frequency is shown in this study. As a forensic lab, non-probative challenging bone samples were tested to highlight the potentials value of using MPS technology – Ion™ 5S. This study shows the first mtGenome data generated for UAE Arabs population which helps extending the current available mtDNA control region database. As a result, this study shows great value of implementing MPS in the routine work in forensic genetics at Dubai Police.

A set of 87 reference samples collected from the population of Saudi Arabia were sequenced using the ForenSeq™DNA Signature Prep Kit on a MiSeq FGx™. The FASTQ files contain the sequences of the SE33 STR, but are not reported by the ForenSeq™ Universal Analysis Software (UAS). The STRait Razor software was used to recover and to report SE33 sequence‐based data for the Saudi population. Ninety-six sequence-based alleles were recovered, most of which had previously reported motif patterns. Two unreported motif patterns found in three alleles and seven novel allele sequences were reported. We also reported a single discordance between the sequence-based data and the CE data that was due to the presence of a common TTTT deletion. SE33 had 130% more sequence-based alleles; the highest number of observed sequence variants were in alleles 27.2 and 30.2, which each had 7 sequence variants. The statistical parameters emphasize the usefulness of using the sequence-based data.

Touch samples by their nature do not contain large amounts of biological material, especially compared to biological fluids such as blood, semen or saliva. Consequently, more careful recovery and storage are desirable in order to maximise the amount of DNA available. The main aim of the work presented is to determine whether detergent-based wetting agents increased DNA yield from touch samples when compared to water as a wetting agent. The results show that the use of the detergent-based lysis buffer led to greater DNA recovery from the fingerprints than when distilled water was used. The use of the lysis buffer in the touch DNA sample collection improved DNA recovery and stability over 24 h post-collection.

The effect of decalcification on pulverised bone samples was studied to evaluate its value when processing reasonably good quality samples. The decalcified and non-decalcified bone samples were extracted using phenol-chloroform extraction method, quantitated with GoTaq ® qPCR Master Mix (Promega ® , UK) using Applied Biosystems ® 7500 Real-Time PCR System (Thermo Fisher Scientific ® , UK) and amplified using an in-house amplification multiplex. The results showed that the decalcification of bone samples is not a necessary when processing good quality samples and higher DNA yields were obtained without the decalcification process. The electropherograms produced from the extracted DNA samples without decalcification were good quality and displayed no PCR inhibition.

The Precision ID Ancestry panel from ThermoFisher contains 165 SNP markers. In this study we compared library construction using the automated workflow with the Ion Chef and a manual workflow. Casework samples that were collected between 2005 and 2018 in the State of Qatar where used for the study and the samples varied from routine stains to challenging samples that yielded full and partial STR profiles. One hundred and forty-three samples were processed: sixteen using both workflows. Full and partial profiles were seen with both methods. The assay was sensitive; one sample with only 0.12 ng of input DNA having a full profile. No significant differences were seen between the two workflows. However, the automated workflow saved considerable hands-on lab time and reduced the potential for pipetting errors.

This study profiled 1047 volunteers using the GlobalFiler™ Kit from the four main ethnic groups in Ghana: the Akan (282), Mole-Dagomba and Northern ethnic minority (253), Ewe (250) and Ga-Dangbe (262), representing about 98.4% ethnic coverage of the Ghanaian population. The polymorphic nature of the African population was demonstrated during the profiling of the reference dataset with the occurrence of some rare triplet variant alleles. At the TPOX locus, three tri-allelic variants were found with the allelic patterns 6-8-10, 8-9-10 and 9-10-11. In addition, tri-allelic patterns were seen at D5S818 (11-13-14) and D3S1358 (15-16-17). Although the TPOX tri-allelic pattern has been reported in other populations including African, the D5S818; 11-13-14 has never been reported in an African population. It has however, been reported once with a frequency of 1 in 69,600 in a convicted offender case in the USA. The D3S1358; 15-16-17 pattern has not been reported in an African population. In conclusion, the occurrence of rare alleles is illustrative of the genetic diversity within the Ghanaian population. This was further illustrated by the presence of three individuals that were heterozygous at all 21 STR loci.

Differentiating male lineages using non-recombining Y-chromosomal genetic markers is highly informative for tracing human migration and for forensic studies. Recently, it has been shown that the level of male lineage resolution can be enhanced by analysing rapidly mutating (RM) Y-STRs. The aim of this study was to develop an allelic frequency database for Qatari population to evaluate the resolution power of 13 RM Y-STRs. The overall haplotype diversity (HD) was 100%. It was found that the markers which contributed the most toward high HD were DYF399S1 and DYF403S1a/b. Together with their value for paternal male relative differentiation, these RM Y-STRs will be a valuable asset for forensic casework. AMOVA test was performed between Qatari population in comparison to Gulf countries, Middle East, and several worldwide population data sets. FST values were also calculated. Geography was found to account considerably for the pattern of population sub structuring. The RM Y-STR markers showed remarkable haplotype resolution power in the Qatari population, high gene diversity and sufficient robustness for a diverse range of applications.

The main focus in forensic genetics for two decades has been to improve the extraction of DNA from a wide variety of evidence and to make the profiling technology more sensitive and robust. In contrast, the recovery methods for biological material have seen little development. This study aims to improve the efficacy of the collection and storage processes, from crime scene to receipt at the laboratory. This study compared the use of ultrapure water as a wetting agent when collecting biological evidence using swabs with a detergent-based buffer. The results show that the stability post-collection greatly improved by using a newly developed buffer. When ultrapure water is used, DNA degradation was seen after 6 h at room temperature. However, the detergent-based buffer stabilized DNA for up to 48 h, even when the temperature was increased to 50 °C. The impact of these findings may be limited where crime scene evidence can be refrigerated until it reaches the laboratory. However, there are many situations/contexts where sample refrigeration is not possible and there is scope to improve the preservation of the genetic forensic evidence before it reaches the laboratory.

In the Ras Al Khaimah DNA Forensic Unit Chelex ® -100 is used when processing biological evidence. However, in many laboratories solid phase extraction techniques have gained popularity. Before changing methodology we wanted to compare the performance of two commonly used methods, the QIAamp ® DNA Investigator Kit (Qiagen, Germany) and the PrepFiler™ lysis buffer using the AutoMate Express™ System (Applied Biosystems). Fresh samples of blood, semen and saliva were placed onto cotton swabs and air-dried before extraction. Evaluation was based on the extracted DNA quantity and quality using real-time quantification (Quantifiler ® Human, Applied Biosystems). Additional criteria such as consistency, ease of use and cost efficiency were also considered. All extraction methods yielded good quality DNA with an IPC value between 27C t and 29C t with the exception of the Chelex ® -100 method when blood samples were processed. One-step analysis of variance showed significant differences in the quantity of DNA recovered between the methods tested ( p =0.0003 for blood, p =6.83e −5 for semen and p =0.002 for saliva). Chelex ® -100 gave the highest yield for semen and saliva and the AutoMate Express™ gave the highest yield when processing blood. Although QIAamp ® DNA Investigator gave lower yields it did produce the most consistent results, with little variation between extracts. Overall the AutoMate Express™ was the most favorable method tested; however Chelex ® -100 is a much cheaper alternative, which does not compromise on DNA yield and in practice rarely suffers from inhibition when processing routine casework.

Development of a new multiplex comprising of 13 Rapidly Mutating Y STRs (RM Y-STR) is presented. The multiplex will aid investigating the human genetic structure of United Arab Emirates (UAE) populations and would also be used to investigate unresolved forensic cases in Dubai Forensic Laboratory. Thirteen markers have been included in the multiplex. A mini validation of the new multiplex has been carried out including specificity, sensitivity and mixture studies. These markers have been analysed in 600 male samples from UAE population. Allelic frequencies, haplotype diversity and discrimination capacity were determined for the 13 RM Y-STRs. Mutations pattern analysis of the RM Y-STR loci in a typical UAE family has also been carried out.

A consequence of armed conflict and other situations of violence is that individuals go missing; these individuals have often been killed and their remains have not been identified or in some cases may be alive but have been separated from their families and are unable to re-establish family links. Forensic genetics provides a powerful tool for the identification of both the dead and living and can be used to assist in identifying missing persons. Guidelines exist that detail technical aspects of human identification using forensic genetics, particularly when identifying victims of disasters such as plane crashes; however, limited emphasis is given to circumstances often faced by investigations of abuses and violations of international humanitarian and human rights' law. The Argentine government's Human Rights Division in the Ministry of Foreign Affairs and Worship (MREC) proposed that the United Nations (UN) should promote best practices in the use of forensic genetics for this type of investigation; this was adopted in Resolutions A/HRC/RES/10/26 and A/HRC/RES/15/5. Following these resolutions MREC has coordinated, with support from the International Committee of the Red Cross (ICRC), the drafting of a set of guidelines, with input from several national and international organisations, which it plans to promote through national agencies, international organisations such as South America's MERCOSUR and the UN.

The analysis of degraded DNA is one of the biggest challenges in forensic casework. SNPs, which can be amplified using small amplicons, have previously been successfully applied to the profiling of forensic evidence that could not be analyzed using conventional STRs. Here we selected the 52 SNPforID SNP markers, with amplicons that ranged in size from 59bp to 115bp, and used them to profile a range of casework samples from Malaysia. DNA degradation is a common problem in Malaysia due to the high temperatures and humidity. To carry out the study we modified the 52 SNPforID markers into four 13-plex SNaPshot assays to enable easier interpretation of profiles on the ABI PRISM ® 310 and 3500. Fifty-one crime samples comprising bloodstains on cloth, swabs, and a mat and 2 swabs of trace DNA from 10 crime scenes in Malaysia were profiled after DNA extraction using a phenol–chloroform method. The samples were also subjected to STR analysis using the Powerplex ® 16 system (Promega), which resulted in only 17 full profiles and 9 partial profiles; using SNPs, 36 full profiles and 5 partial profiles could be generated.

In sexual assault cases DNA profiling of spermatozoa can be of critical importance. Most methods use differential extraction of the spermatozoa to separate it from the female component. Here we have compared two commercially available differential extraction methods, the QIAamp ® DNA mini kit (Qiagen) and Differex™ with the DNA IQ ® System (Promega). Simulated postcoital samples were prepared using buccal cells from a female donor and spermatozoa from three male donors. A dilution series ranging from neat semen to a 1:1500 dilution (semen:dH 2 O) was prepared and mixed with an equal volume of saliva from a female donor. Extraction efficiency was assessed using DNA concentration measured with NanoDrop 2000 and Quantifiler ® Human DNA Quantification Kit and the profile count of full, partial and mixed DNA profiles generated using SGM Plus and PowerPlex ® ESI 17. Statistical analysis was carried out using Randomisation in R, which is a robust model making no assumption of the distribution of data. Based on the amount of DNA extracted and the types of profiles no significant difference in the performance of the two extraction kits was seen. However, the processing time taken with the Differex™ System was about half than that of the QIAamp ® DNA mini kit and involved fewer liquid transfers.

Five DNA extraction systems were assessed for their DNA extraction efficiency on samples of fresh pig bone. Four commercially available silica-based extraction kits (ChargeSwitch ® gDNA Plant Kit (Life Technologies), DNA IQ TM System Kit (Promega), DNeasy ® Blood & Tissue Kit (Qiagen) and PrepFiler ® BTA Forensic DNA Extraction Kit (Life Technologies)) and a conventional phenol-chloroform method were tested in this study. Extracted DNA samples were quantitated with GoTaq ® qPCR Master Mix (Promega) using an Applied Biosystems ® 7500 Real-Time PCR System and the extracts were amplified using an in-house multiplex system. The phenol-chloroform extraction produced higher yields of DNA than the silica-based extraction methods. Among the silica-based extractions ChargeSwitch ® gDNA Plant Kit recovered the highest amounts of DNA. However, all methods produced DNA that could be amplified and none of the extracts contained any detectable inhibition.

In order to assess DNA degradation in the model organisms chosen (pig and rabbit), two nuclear genes, Connexin 43 and RAG-1, were aligned to identify conserved regions. Primers were designed to amplify 70 bp, 194 bp, 305 bp and 384 bp amplicons. The primers were also designed to amplify human DNA, which allowed the use of commercially purchased DNA standards to be used as controls. Following DNA extraction PCR analysis was performed using the four primers sets in a multiplex (4-plex): the PCR was optimised so that it worked over a wide range of template amounts (0.1–75.83 ng). The multiplex (4-plex) PCR was found to work efficiently in triplicate samples with all three species down to 0.3 ng of DNA template. This multiplex has been used to assess whether DNA degradation can be predicted by accumulated degree-days (ADD), which provides a measure of both time and temperature. Full 4-plex profiles were generated until day 7 (112 ADD) from whole carcasses and body fragments. Future work will include; development of real-time PCR quantification assays, DNA fragment analysis and DNA preservation.

The analysis of Y chromosome polymorphisms has become common place for the identification of male component in forensic cases. During the development of a Y STR population database for three major populations in the United Arab Emirates (Arab, Indian and Pakistani) using the AmpFlSTR ® Y Filer™ kit, a number of novel and null alleles were discovered.

Gross morphology, histology and nitrogen content were examined in bone samples from individuals that had been buried for approximately 12 years in Kuwait and Iraq. The results indicate that the gross morphology and histology are useful indicators of DNA survival. Nitrogen content did not show a significant correlation with DNA preservation.