Forensic DNA extraction methods for human hard tissue: A systematic literature review and meta-analysis of technologies and sample type

Nails as optimal source of DNA for molecular identification of 5 decomposed bodies recovered from seawater: from Y-ancestry to personal identification

Molecular identification of extremely compromised human remains in forensic field is usually performed from DNA typing of bones, which are a difficult sample to work with. Moreover, autosomal STR profiles do not always result in the identification of the donor due to lack of comparisons or non-hit throughout database searching. An attempt to overcome these issues is represented by fingernails as an alternative DNA source and Y-STRs typing to infer both geographical and familial ancestry of the unknown donor. In this study, we analyzed both 24 autosomal and 27 Y-chromosome STRs from unidentified human remains (UHRs) of five males recovered from the water near the southwestern coast of Sardinia by the Italian Harbor Master's Office. Nail clippings provided an optimal source of autologous DNA for molecular identification in a very short time, producing complete autosomal and Y-STR profiles even under conditions of high body degradation. Unfortunately, no match neither compatibility occurred using autosomal STRs (aSTRs), initially. Upon analyzing the Y-haplotypes, we found out they had already been observed in northern Africa, providing us important investigative leads. This prompted the International Criminal Police Organization (INTERPOL) to provide us with references of alleged relatives that were then confirmed to be related. The use of fingernails represents an excellent DNA source especially for genetic identification of decomposed bodies recovered in seawater environment. Notably, DNA extracted from nails gave high-quality Y-STR haplotypes by which predicting paternal ancestry of the unidentified donors may result fundamental in the forensic investigative context.

Assessment of the efficiency of DNA isolation and profiling applying a temperature-driven method in human remains

The identification of human remains is of utmost importance in a variety of scenarios. One of the primary identification methods is DNA. DNA extraction from human remains could be difficult, particularly in situations where the remains have been exposed to environmental conditions and other insults. Several studies tried to improve extraction by applying different approaches. ForensicGEM Universal (MicroGem) is a single-tube approach to DNA extraction and a temperature-driven method that could have some advantages with respect to previous techniques, among them, reducing the risk of contamination, not requiring specialized equipment, or several steps to perform. The aim of this study was to assess, for the first time, the efficiency of DNA extraction and quality of STR profiles applying the MicroGem protocol and modifications of this protocol from tooth samples in comparison with automatic extraction (AE). Our results indicated that AE and MicroGem performed similar, though with variability depending on the MicroGem modifications, increasing the DNA yield and STR profile quality when DNA is concentrated with Microcon. These findings demonstrated the efficiency of this methodology for DNA extraction from human remains while also providing a simple and quick technique suitable to apply in a variety of forensic scenarios.

An optimal skeletal element for DNA testing: Evaluation of DNA quantity and quality from various bone types in routine forensic practice

For human identification, the quality and quantity of DNA must be sufficient for amplification and analysis. When DNA extraction from bone tissues and teeth is required, the optimal skeletal elements should be selected as samples for DNA extraction because DNA yield differs among elements. Recently, some studies have reported that a high quantity of high-quality DNA can be extracted from the small cancellous bones of the hands and feet. In this study, we evaluated the effectiveness of small cancellous bones in the human identification of skeletal remains in routine forensic genetic casework. Cancellous bones [phalanges, (meta)carpal bones, and (meta)tarsal bones)] and the cortical bones (femur and petrous bones) and teeth, which have generally been recommended as samples, were collected from the same individuals that needed identifying using DNA analysis in our laboratory. The quantity of DNA from small cancellous bones tended to be higher than that from cortical bones, and the quality from the former was as high as that from the latter. This study showed that in routine forensic casework, the small cancellous bones of the hands and feet should be actively selected as samples for DNA testing.

Cost analysis of archives in the pathology laboratories: from safety to management

CONTEXT

Despite the reluctance to invest and the challenging estimation of necessary supporting costs, optimising the archives seems to be one of the hottest topics in the future management of the pathology laboratories. Historically, archives were only partially designed to securely store and organise tissue specimens, and tracking systems were often flawed, posing significant risks to patients' health and legal ramifications for pathologists.

OBJECTIVE

The current review explores the available data from the literature on archives' management in pathology, including comprehensive business plans, structure setup, outfit, inventories, ongoing conservation and functional charges.

DATA SOURCES

Electronic searches in PubMed-MEDLINE and Embase were made to extract pertinent articles from the literature. Works about the archiving process and storage were included and analysed to extract information. Prepublication servers were ignored. Italian Institutional Regional databases for public competitive bidding processes were queried too.

CONCLUSIONS

A new emergent feeling in the pathology laboratory is growing for archives management; the digital pathology era is a great opportunity to apply innovation to tracking systems and samples preservation. The main aim is a critical evaluation of the return of investment in developing automatic and tracked archiving processes for improving not only quality, efficacy and efficiency of the labs but also patients' healthcare.

A comparison between petrous bone and tooth, femur and tibia DNA analysis from degraded skeletal remains

Skeletal remains are the only biological material that remains after long periods; however, environmental conditions such as temperature, humidity, and pH affect DNA preservation, turning skeletal remains into a challenging sample for DNA laboratories. Sample selection is a key factor, and femur and tooth have been traditionally recommended as the best substrate of genetic material. Recently, petrous bone (cochlear area) has been suggested as a better option due to its DNA yield. This research aims to evaluate the efficiency of petrous bone compared to other cranium samples (tooth) and postcranial long bones (femur and tibia). A total amount of 88 samples were selected from 38 different individuals. The samples were extracted by using an organic extraction protocol, DNA quantification by Quantifiler Trio kit and amplified with GlobalFiler kit. Results show that petrous bone outperforms other bone remains in quantification data, yielding 15-30 times more DNA than the others. DNA profile data presented likeness between petrous bone and tooth regarding detected alleles; however, the amount of DNA extracted in petrous bones allowed us to obtain more informative DNA profiles with superior quality. In conclusion, petrous bone or teeth sampling is recommended if DNA typing is going to be performed with environmentally degraded skeletal remains.

Evaluating the Usefulness of Human DNA Quantification to Predict DNA Profiling Success of Historical Bone Samples

This study assessed the usefulness of DNA quantification to predict the success of historical samples when analyzing SNPs, mtDNA, and STR targets. Thirty burials from six historical contexts were utilized, ranging in age from 80 to 800 years postmortem. Samples underwent library preparation and hybridization capture with two bait panels (FORCE and mitogenome), and STR typing (autosomal STR and Y-STR). All 30 samples generated small (~80 bp) autosomal DNA target qPCR results, despite mean mappable fragments ranging from 55-125 bp. The qPCR results were positively correlated with DNA profiling success. Samples with human DNA inputs as low as 100 pg resulted in ≥80% FORCE SNPs at 10X coverage. All 30 samples resulted in mitogenome coverage ≥100X despite low human DNA input (as low as 1 pg). With PowerPlex Fusion, ≥30 pg human DNA input resulted in >40% of auSTR loci. At least 59% of Y-STR loci were recovered with Y-target qPCR-based inputs of ≥24 pg. The results also indicate that human DNA quantity is a better predictor of success than the ratio of human to exogenous DNA. Accurate quantification with qPCR is feasible for historical bone samples, allowing for the screening of extracts to predict the success of DNA profiling.

Impact of a centralized archive for pathology laboratories on the health system

The pathology archive of any hospital is likely to contain tens of thousands of slides and formalin-fixed and paraffin-embedded (FFPE) blocks, with their number constantly increasing. As a result, serious space and management issues are created. There has always been a favorable location for the pathology laboratory to rapidly and efficiently collect specimens and to meet the different service requirements of clinicians and patients. However, archiving may be one of the most neglected issues in the planning of spaces and activities, so much so that many laboratories are currently in trouble and looking for space inside and outside their hospitals. Another crucial issue is related to the environmental conditions of the identified preservation place, which, based on their characteristics, probably provide suboptimal habitats in most cases. For FFPE blocks, controlled temperature (<27 °C) and humidity (>30% and <70%) are recommended, with control systems for parasite infestation. For glass slides, systems suitable for guaranteeing their safety, traceability and conservation suitable for possible revision are recommended. The aim of this position paper is to outline the issues that currently exist in archives and to suggest a rational health policy solution to overcome the problems raised.