Palaeomicrobiology meets forensic medicine: time as a fourth-dimension for the crime scene.

The unrelenting progress of laboratory techniques is rapidly unleashing the huge potential of palaeomicrobiology. That bodies are often found in poor condition is common to both palaeomicrobiology and forensic medicine, and this might stimulate them towards a joint quest to extract reproducible data for reliable specimens.

Development of an Italian RM Y-STR haplotype database: Results of the 2013 GEFI collaborative exercise.

Recently introduced rapidly mutating Y-chromosomal short tandem repeat (RM Y-STR) loci, displaying a multiple-fold higher mutation rate relative to any other Y-STRs, including those conventionally used in forensic casework, have been demonstrated to improve the resolution of male lineage differentiation and to allow male relative separation usually impossible with standard Y-STRs. However, large and geographically-detailed frequency haplotype databases are required to estimate the statistical weight of RM Y-STR haplotype matches if observed in forensic casework. With this in mind, the Italian Working Group (GEFI) of the International Society for Forensic Genetics launched a collaborative exercise aimed at generating an Italian quality controlled forensic RM Y-STR haplotype database. Overall 1509 male individuals from 13 regional populations covering northern, central and southern areas of the Italian peninsula plus Sicily were collected, including both "rural" and "urban" samples classified according to population density in the sampling area. A subset of individuals was additionally genotyped for Y-STR loci included in the Yfiler and PowerPlex Y23 (PPY23) systems (75% and 62%, respectively), allowing the comparison of RM and conventional Y-STRs. Considering the whole set of 13 RM Y-STRs, 1501 unique haplotypes were observed among the 1509 sampled Italian men with a haplotype diversity of 0.999996, largely superior to Yfiler and PPY23 with 0.999914 and 0.999950, respectively. AMOVA indicated that 99.996% of the haplotype variation was within populations, confirming that genetic-geographic structure is almost undetected by RM Y-STRs. Haplotype sharing among regional Italian populations was not observed at all with the complete set of 13 RM Y-STRs. Haplotype sharing within Italian populations was very rare (0.27% non-unique haplotypes), and lower in urban (0.22%) than rural (0.29%) areas. Additionally, 422 father-son pairs were investigated, and 20.1% of them could be discriminated by the whole set of 13 RM Y-STRs, which was very close to the theoretically expected estimate of 19.5% given the mutation rates of the markers used. Results obtained from a high-coverage Italian haplotype dataset confirm on the regional scale the exceptional ability of RM Y-STRs to resolve male lineages previously observed globally, and attest the unsurpassed value of RM Y-STRs for male-relative differentiation purposes.

The 2011 GeFI collaborative exercise. Concordance study, proficiency testing and Italian population data on the new ENFSI/EDNAP loci D1S1656, D2S441, D10S1248, D12S391, D22S1045.

The 2011 collaborative exercise of the ISFG Italian Working Group GeFI was aimed at validating the five ENFSI/EDNAP miniSTR loci D1S1656, D2S441, D10S1248, D12S391 and D22S1045. The protocol required to type at least 50 multilocus profiles from locally resident individuals and two blind bloodstains in duplicate (i.e., using at least two different commercial kits), and to send the electropherograms to the Organizing Committee. Nineteen laboratories distributed across Italy participated, collecting a total of 960 samples. Full concordance was found for the five new miniSTRs as observed from the comparison of 13,150 alleles. The inspection of the electropherograms allowed the identification of a very limited number of mistypings in the miniSTR genotypes thus contributing to the establishment of an high quality Italian database of frequencies.

Italian population data for D1S1656, D3S1358, D8S1132, D10S2325, VWA, FES/FPS, and F13A01.

Allele frequencies for seven STRs loci were obtained from a sample of 215 unrelated healthy Italian individuals.

Northeast Italy population data using multiplex PCR (HUMCD4, HUMTH01, HUMTPOX, and HUMCSF1P0) loci.

Allele and genotype frequencies for four short tandem repeat (STR) loci (HUMCD4, HUMTH01, HUMTPOX, and HUMCSF1P0) were determined in 100 unrelated individuals from Veneto (Northeast Italy). After a multiplex polymerase chain reaction (PCR)-amplification, semi-automatic DNA profiling was performed using an A.L.F.express DNA Sequencer. Conditions were optimized for the PCR co-amplification of these four STR loci and the quadruplex PCR was performed on various forensic DNA samples such as whole blood, blood-stains, teeth, and saliva from Caucasians living in the Northeast Italy. The distribution of the genotype frequencies showed no significant deviation from Hardy-Weinberg expectations in the sampled population. The combined Power of Discrimination (PD) of the quadruplex was 0.9999.

Effects of individual dental factors on genomic DNA analysis.

The use in forensic medicine of methods pertaining to molecular biology has made it possible to identify human remains through the analysis of polymorphic profiles of human DNA. Voluntary, accidental, or natural postmortem degradation, as well as environmental conditions, influences the preservation state of the corpse, making it sometimes difficult to obtain biologic material suitable for genetic analysis (e.g., hair, soft and/or hard tissue). According to their anatomic/morphologic characteristics, dental formations are particularly resistant to external insults and are thus suitable for this kind of research. The purpose of this work, conducted on nonselected dental findings (presenting intrinsic characteristics similar to those usually found in forensic cases) that were homogeneous with regard to environmental factors, was to determine an operative protocol that will enable combination of the maximum availability of genomic DNA with the preservation of the morphologic characteristics of the tooth for classic anthropologic evaluations.

Determination of illicit and/or abused drugs and compounds of forensic interest in biosamples by capillary electrophoretic/electrokinetic methods.

The application of capillary electrophoresis (CE) methods in forensic toxicology for the determination of illicit and/or misused drugs in biological samples is reviewed in the present paper. Sample pretreatments and direct injection modes used in CE for analysis of drugs in biological fluids are briefly described. Besides, applications of separation methods based on capillary zone electrophoresis or micellar electrokinetic chromatography with UV absorbance detection to (i) analysis of drugs of abuse, (ii) analysis of other drugs and toxicants of potential forensic interest and (iii) for metabolism studies are reviewed. Also, alternative CE methods are briefly discussed, including capillary isotachophoresis and separation on mixed polymer networks. High sensitivity detection methods used for forensic drug analysis in biological samples are then presented, particularly those based on laser induced fluorescence. A glimpse of the first examples of application of CE-mass spectrometry in forensic toxicology is finally given.

Optimization of a simple method for the chiral separation of phenethylamines of forensic interest based on cyclodextrin complexation capillary electrophoresis and its preliminary application to the analysis of human urine and hair.

Because of the forensic importance of the chiral analysis of amphetamine and other phenethylamines for investigating their synthetic pathways and the metabolic patterns of these compounds, a capillary electrophoresis method has been developed based on the chiral selectivity of beta-cyclodextrin. The influence of different experimental conditions, such as cyclodextrin nature and concentration, voltage, temperature and buffer concentration and pH, on analytical performance has been studied. The optimized analytical conditions are: capillary: bare fused silica, 50 microns I.D., 40 cm effective length; buffer: 150 mM phosphate pH = 2.5, 15 mM beta-cyclodextrin; voltage: 10 kV; temperature: 17.5 degrees C; detection: UV absorption at 200 nm wavelength. Under these conditions, amphetamine, methamphetamine and ephedrine have been easily separated, with baseline resolution of the respective enantiomers. Sensitivity was better than 300 ng per ml. The average precision of migration times of the three analytes was good with RSD = 0.45% and 0.58% in intra-day and day-to-day tests, respectively. Reproducibility of peak heights was also good, with RSD = 2.51% and 3.14% in intra-day and day-to-day tests, respectively. The preliminary analysis of amphetamine in human urine and hair samples, subjected to a simple work-up procedure based on liquid-liquid extraction, showed clean blank electropherograms, excellent chiral resolution and sensitivity, suitable for the analysis of real samples from amphetamine users.

Complementary use of capillary zone electrophoresis and micellar electrokinetic capillary chromatography for mutual confirmation of results in forensic drug analysis.

The purpose of this work was to compare different CE separation modes namely capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC) for the analysis of drugs of forensic interest in order to assess the mutual degree of independence and consequently the possibility of complementary use for mutual confirmation of results. A panel of drugs including caffeine, morphine, barbital, pentobarbital, codeine, nalorphine, lidocaine, procaine, heroin, flunitrazepam, acetylcodeine, papaverine, amphetamine, narcotine, cocaine, diazepam, tetracaine, narceine, 6-monoacetylmorphine acetylcodeine and thebaine, were separated according to a MECC and two CZE methods. The MECC separation was carried out in a bare silica capillary (50 micron I.D.) with a buffer composed of 25 mM borate (pH 9.24)--20% methanol--100 mM sodium dodecyl sulphate; the applied voltage was 20 kV. The first CZE method (CZE1) was carried out in 50 mM phosphate buffer (pH 2.35) at 20 kV with a bare silica capillary (50 micron I.D.), and the second (CZE2) with 50 mM borate (pH 9.24) at 12 kV with the same capillary. The three methods were effective in the separation of the test drug mixture, but MECC was the only able to resolve all the components. Relative (to flunitrazepam), migration time RSDs ranged from 0.3 to 2.8% for the three methods were compared with Spearman's test and with principal component analysis, CZE1 and CZE2 were significantly and directly correlated (r = 0.749, p < 0.002), whereas MECC and CZE2 were also significantly, but inversely correlated (r = -0.865, p < 0.001). MECC and CZE1 (limitedly to the basic drugs) appeared non-correlated (r= -0.131, p = 0.630) and therefore the two techniques are suitable for combined use to increase the discriminatory power.

Capillary electrophoresis: principles and applications in illicit drug analysis.

Capillary electrophoresis, which appeared in the early 1980s, is now rapidly expanding into many scientific disciplines, including analytical chemistry, biotechnology and biomedical and pharmaceutical sciences. In capillary electrophoresis,electrokinetic separations are carried out in tiny capillaries at high voltages (10-30 kV), thus obtaining high efficiencies (N > 10(5)) and excellent mass sensitivities (down to 10(-18)-10(-20) moles). The main features of capillary electrophoresis are: versatility of application (from inorganic ions to large DNA fragments), use of different separation modes with different selectivity, extremely low demands on sample volume, negligible running costs, possibility of interfacing with different detection systems, ruggedness and simplicity of instrumentation. Capillary electrophoresis applications in forensic sciences have appeared only recently, but are now rapidly growing, particularly in forensic toxicology. The present paper briefly describes the basic principles of capillary electrophoresis, from both the instrumental and analytical points of view. Furthermore, the main applications in the analysis of illicit/controlled drugs in both illicit preparations and biological samples are presented and discussed (43 references). It is concluded that the particular separation mechanism and the high complementarity of this technique to chromatography makes capillary electrophoresis a new powerful tool of investigation in the hands of forensic toxicologists.

Capillary electrophoresis: a new tool in forensic toxicology. Applications and prospects in hair analysis for illicit drugs.

Capillary electrophoresis, the modern approach to instrumental electrophoresis, is probably the most rapidly expanding analytical technique that has appeared in recent years. In the hands of forensic toxicologists, capillary electrophoresis (CE) represents a powerful new analytical tool, which has proved suitable for the investigation of illicit drugs in seized preparations and also in complex biological matrices, among which is hair. CE can be applied according to different separation mechanisms, and among those that are toxicologically relevant are capillary zone electrophoresis and micellar electrokinetic capillary chromatography, which display different selectivities. For the investigation of hair for drugs of abuse, capillary electrophoresis proved effective, providing simultaneous determinations of different drugs without derivatization, with acceptable sensitivity (typically better than 1 ng of drug per mg of hair). The possibility of carrying out determinations of the same analytes, based on different separation mechanisms (capillary zone electrophoresis and micellar electrokinetic chromatography) with the same instrumentation, simply changing the buffer composition, provides an interesting possibility of 'internal' confirmation of the results.