Use of deoxyribonucleic acid (DNA) fingerprints for identity determination: comparison with traditional paternity testing methods--Part I

A study involving comparison of the deoxyribonucleic acid (DNA) finger-printing test with traditional methods used for paternity testing is presented. Samples from 191 cases were tested for a series of blood group and polymorphic protein markers. DNA "fingerprints" were then obtained for all samples using the multilocus probes 33.6 and 33.15. The results of DNA fingerprinting correlated well with those of traditional methods and proved to be informative in cases where traditional methods yielded inconclusive or insufficient results.     

Use of deoxyribonucleic acid (DNA) fingerprints for identity determination: comparison with traditional paternity testing methods--Part II

Six red blood cell (RBC) antigen systems, coupled with human lymphocyte antigen (HLA) phenotyping, were used to establish paternity on 28 mother/child/alleged-father trios. Samples were subsequently examined using the deoxyribonucleic acid (DNA) fingerprinting test with the multilocus Jeffreys DNA probes 33.6 and 33.15. In 27 of 28 paternity cases, the DNA fingerprinting test results supported and enhanced the results of RBC and HLA typing by resolving disputed paternity cases conclusively. One discrepancy between conventional serological methods and DNA analysis is discussed.     

Big game species identification by deoxyribonucleic acid (DNA) probes.

Species identification is important in many big game forensic science cases but cannot always be accomplished because of the lack of adequate techniques. The authors have developed deoxyribonucleic acid (DNA) probes for elk, deer, and antelope by isolating highly repeated satellite sequences. These DNA probes distinguish among deer, elk, and antelope, although not between different species of deer. Because of the high number of sequence copies per genome, these probes are extremely sensitive, requiring less than 10 ng of total genomic DNA. The developmental protocol for these probes is relatively simple and is applicable to many other species.     

DNA profile evidence in complex disputed paternity cases: The analysis of 300 real cases

In disputed paternity cases where the putative father is unavailable DNA from one or more of his relatives could be used. However, interpreting results is often difficult, because of the partial information regarding the parental genotype obtained from his relatives. We analyzed results obtained in 300 real paternity cases performed through close relatives of the real father (sib, half-sibs, one grandparent and/or uncle). DNA was typed with PowerPlex (Promega) and the LR estimated with the Software BDGen. As expected the higher LR values were achieved with sibs and half-sibs (in such cases where his/her mother was available for testing). The LR values were tight related to the number of uninformative loci, which varied between 0 and 13. In 10% of the reviewed cases, 10 or more non-informative loci were observed; all of them associated LR values below 0.01. Thus, providing evidence in favor of no relatedness.     

Further evidence of a silent plasminogen (PLG) allele in two paternity cases

Routine paternity testing has yielded two different cases of an apparent inverse homozygosity in the plasminogen (PLG) system. In one case, the child presented the phenotype PLG A and his putative father the type PLG B. The alleged father could not be excluded from the paternity in 25 additional blood group marker systems (biostatistical probability of paternity W greater than 99.75%). In the other case an incompatibility was found in a mother- child pair. Analysis of PLG was carried out by isoelectric focusing on neuraminidase-treated sera. In both cases the immunologic and functional detection showed weaker banding pattern of the affected PLG types. The assumption of a silent allele in the PLG system was confirmed by quantitative investigations. The allele frequency of PLG*Q0 in the South German population was estimated to be 0.0013. In the same sample the variant PLG A3 has been shown to be polymorphic.     

Characterization of deoxyribonucleic acid (DNA) obtained from teeth subjected to various environmental conditions.

This study was designed to determine the effects of various environmental factors on the deoxyribonucleic acid (DNA) obtained from dental pulp. Extracted teeth were subjected to the following conditions: varying pH (3,7,10); temperature (4 degrees C, 25 degrees C, 37 degrees C, incineration); humidity (20%, 66%, 98%); various types of soil (sand, potting soil, garden soil); seawater; burying the teeth outdoors, and aging (one week to six months). In addition, teeth that had been extracted and held at room temperature for 16 and 19 years were also examined. Following isolation of DNA, the samples were analyzed on yield gels to determine the concentration and integrity of the recovered DNA. Restriction digestion with Pst I was followed by electrophoresis of the generated fragments, Southern transfer to nylon membranes, and hybridization to both human and bacterial probes. It was determined that, aside from soil, the environmental conditions examined did not affect the ability to obtain high-molecular-weight human DNA from dental pulp. Restriction fragment length polymorphic (RFLP) analysis of selected samples was performed. Dental pulp patterns were compared with bloodstain exemplars, revealing matching patterns, although an increase in band-shifting was observed with extended exposure to elevated temperatures.     

"Sexing" deoxyribonucleic acid (DNA) on DNA fingerprint gel: an internal control for DNA fingerprint evidence

Deoxyribonucleic acid (DNA) isolated from male and female fresh blood samples was processed exactly as for routine DNA fingerprint analysis; that is, the DNA was digested with particular restriction endonucleases and fractionated by agarose gel electrophoresis. Ultraviolet (UV) visualization of ethidium-bromide (EtBr)-stained gels revealed a sex-specific banding pattern, which depended only on the restriction enzyme used. By means of this test, which is based on direct detection of particular sex-specific restriction fragments in human DNA digests, the authors succeeded in determining the sex of DNA obtained from biological specimens recovered as criminal evidence in rape cases. The data obtained demonstrate that direct sexing of DNA on DNA fingerprint gel appears to be useful as an intermediate control step in DNA fingerprinting analysis used for the purpose of assailant identification.     

Individual identification from semen by the deoxyribonucleic acid (DNA) fingerprint technique

For individual identification from semen, the deoxyribonucleic acid (DNA) fingerprint technique was used. In a blind trial, we succeeded in determining the semen donors among several volunteers comparing the DNA fingerprints of the blood and semen samples, respectively. Thereafter, we examined semen in a condom left beside a naked female dead body. The DNA fingerprint of the semen was recognized to be identical to that of the blood from a suspected man arrested later. This is the first report that the DNA fingerprint technique was practically used in a criminal investigation in Japan.     

Typing of deoxyribonucleic acid (DNA) extracted from compact bone from human remains.

The application of deoxyribonucleic acid (DNA) typing methods for the potential identification of unknown human remains was investigated. DNA was isolated from compact bone tissue from badly decomposed bodies and from known and unknown human remains, using a decalcification and ion wash procedure. Restriction fragment length polymorphism (RFLP) analysis of variable number of tandem repeats (VNTR) loci yielded results in some cases, but more often the DNA was too degraded to produce RFLP patterns. No RFLP profiles could be obtained from putrefied soft tissues. However, DNA extracted from compact bone tissue of human remains up to eleven years old was successfully amplified using the polymerase chain reaction (PCR) for the VNTR loci D1S80, D17S5, COL2A1, and APO B, as well as the HLA-DQ alpha locus. This is especially significant, since PCR results were obtained from those samples whose DNA had been degraded substantially and had yielded no RFLP patterns. All DNA types determined from the compact bone tissue from decomposed bodies whose identification had been established first by other means (and whose parents or offspring were available for typing) demonstrated mendelian inheritance of the alleles of the loci analyzed. These results suggest that amplification and typing of DNA extracted from compact bone of human remains could be useful in establishing the identity of a person, as well as in excluding possible false identifications.     

Analysis of restriction fragment length polymorphisms in deoxyribonucleic acid (DNA) recovered from dried bloodstains

Deoxyribonucleic acid (DNA) was recovered from dried bloodstains aged up to three years and shown to be of high molecular weight. DNA was digested with restriction endonucleases and fractionated by agarose gel electrophoresis. Following transfer to a filter, DNA was hybridized with two different radioactively labeled recombinant probes which recognize highly polymorphic regions in human DNA. The autoradiographic pattern observed was not altered by sample age, and the size of the alleles was consistent with those observed in the general population. Therefore, DNA of high molecular weight prepared from dried blood samples can be used for identification.     

Isolation of deoxyribonucleic acid (DNA) from saliva and forensic science samples containing saliva.

Saliva and saliva-stained materials were examined as potential sources of deoxyribonucleic acid (DNA) for DNA analysis and identity testing. In this paper, the authors demonstrate that DNA was isolated and DNA banding patterns suitable for DNA typing were obtained from fresh saliva and various saliva-stained materials, such as envelopes, buccal swabs, gags, and cigarettes. Furthermore, DNA and DNA banding patterns were obtained from actual forensic evidentiary samples containing mixed saliva/semen stains. The DNA banding patterns obtained from saliva or saliva-stained material were indistinguishable from the patterns obtained from blood or hair from the same individual. Intact DNA was readily isolated and DNA banding patterns were obtained from saliva stored at -20 degrees C and dried saliva stains stored under varying conditions. We conclude that saliva and saliva-stained material can be good sources of DNA for analysis and for DNA typing in certain forensic settings.     

Identification of decomposed human remains by deoxyribonucleic acid (DNA) profiling

After routine methods failed to establish positive identification of a decomposed homicide victim, deoxyribonucleic acid (DNA) typing techniques using blood from the victim and putative parents of the victim were used. This is the first report in the literature of a case using DNA fingerprinting in a "parentage" context to establish identity of unidentified, decomposed human remains.     

Repetitive deoxyribonucleic acid (DNA) and human genome variation--a concise review relevant to forensic biology

The various classes of human repetitive deoxyribonucleic acid (DNA) are described, with particular emphasis being given to their variation in the human genome. The significance of this information to forensic science is discussed.     

Evaluation of deoxyribonucleic acid (DNA) isolated from human bloodstains exposed to ultraviolet light, heat, humidity, and soil contamination

This study was designed to analyze the effects of common environmental insults on the ability to obtain deoxyribonucleic acid (DNA) restriction fragment-length polymorphisms (RFLP) patterns from laboratory prepared specimens. The environmental conditions studied include the exposure of dried bloodstains to varying amounts of relative humidity (0, 33, 67, and 98%), heat (37 degrees C), and ultraviolet light for periods of up to five days. In addition, the effect of drying over a four-day period in whole blood collected with and without ethylenediaminetetraacetate (EDTA) was examined. The results of the study showed that, under the conditions studied, the integrity of DNA is not altered such that false RFLP patterns are obtained. The only effect observed was that the overall RFLP pattern becomes weaker, but individual RFLP fragments are neither created nor destroyed.     

The autodegradation of deoxyribonucleic acid (DNA) in human rib bone and its relationship to the time interval since death

This research explored the feasibility of using the degradation rate of deoxyribonucleic acid (DNA) in human rib bone to determine the time interval since death. Postmortem human rib samples were surface sterilized and incubated under sterile conditions in either high or low humidity conditions at room temperature for a period of weeks. At selected times, portions of the bone were cut away, and the DNA from these samples was extracted and subjected to strand separating gel electrophoresis. The DNAs in the gels were transferred to a nylon membrane, preserving their relative positions as in the gel, and probed with radioactive total genomic human DNA. Autoradiograms produced were scanned and digitized. When the samples were incubated under identical conditions, the degradation rate of DNA in samples from different individuals appeared very similar. The DNA degradation rate may vary with temperature and humidity more than it varies between individuals.     

Sex identification in fresh blood and dried bloodstains by a nonisotopic deoxyribonucleic acid (DNA) analyzing technique

Deoxyribonucleic acid (DNA) specimens were prepared from blood or bloodstain extracts, and the content of a Y-chromosome specific DNA fragment was investigated by the Southern hybridization method using a nonisotopic staining technique. Thus obtained patterns of male DNA showed a clear band, whereas broad stains with some faint bands appeared on the patterns of DNA from both sexes. This method is expected to be a new powerful mean of forensic medical examination.     

The effects of environment and substrata on deoxyribonucleic acid (DNA): the use of casework samples from New York City

This study was designed to analyze the effects of the environment and substrata on the quality of deoxyribonucleic acid (DNA) isolated from evidentiary specimens. The quality of DNA isolated from actual casework specimens was determined by measuring its size by agarose gel electrophoresis. The information obtained could be used to predict the suitability of the DNA in the samples for restriction fragment length polymorphism (RFLP) analysis. The evidentiary specimens chosen for DNA were classified according to substrate (scrapings, plastic bags, synthetics, denim, and carpet) and according to a subjective evaluation of the condition of the stain (soiled, damp, or putrefied) and to its size (small or large). The results show that DNA of sufficient quality and high molecular weight (HMW) can be reliably isolated from bloodstains deposited on evidentiary items which have an unknown environmental history and which have dried onto a variety of substrata. Subsequent RFLP analysis of a selected number of these samples verified that the DNA was suitable for this type of analysis.     

Identification of male bloodstains by dot hybridization of human Y chromosome-specific deoxyribonucleic acid (DNA) probe

The sex determination of bloodstains was performed using a human Y chromosome-specific (DNA) fragment of 1.9-kb length as a hybridization probe. The DNA samples were taken from 1- and 4-week-old bloodstains of males and females, respectively. Strong signals with male DNA were observed by Y-probe, while faint signals with female DNA were detected. In addition, clear signals were observed in the extract samples from male bloodstains (16-week-old) on paper. Dot hybridization of the Y-probe would be widely applicable to studies on sex determination of medicolegal materials such as blood, bloodstains, teeth, and cadaverous parts.     

Sensitive and specific quantification of human genomic deoxyribonucleic acid (DNA) in forensic science specimens: casework examples.

We describe the forensic science application of a method for quantification of human genomic deoxyribonucleic acid (DNA). The two cases cited in this report involve DNA samples extracted from skin tissue and bloodstained clothing recovered from different crime scenes. High-molecular-weight DNA was recovered from both specimens, and the concentrations of these DNAs were estimated to be approximately 0.5 microgram/microL by ethidium bromide/agarose gel electrophoresis. Using the human-specific DNA probe p17H8 (locus D17Z1) to quantify the amount of human genomic DNA in these samples, it is shown that less than 1% of the DNA isolated from the skin tissue is of human origin and that the DNA isolated from the bloodstained clothing is effectively devoid of human DNA sequences. These case examples illustrate the need to quantify not only the total amount of DNA recovered from forensic casework material, but also the proportion of the DNA that is of human origin.     

Development of a deoxyribonucleic acid (DNA) restriction fragment length polymorphism (RFLP) database for Punjabis in East Punjab,India

In response to continuing interest in obtaining reference deoxyribonucleic acid (DNA) analysis data for previously unstudied population groups, blood samples were collected from Punjabi individuals living in East Punjab, India. This first segment of our research is focused on restriction fragment length polymorphism (RFLP) analysis, with future segments anticipated for various polymerase chain reaction (PCR) based techniques. In this study, the samples were subjected to RFLP analysis using HaeIII, followed by hybridization with variable number tandem repeat (VNTR) probes for loci D2S44, D1S7, D10S28, D4S139, D17S79 and D5S110. The band sizes of the resulting patterns were estimated using an FBI imaging system. The resulting data were subjected to statistical analysis for conformity with Hardy-Weinberg expectations, first for the total population of Punjabis, and additionally for the subgroups of Sikhs and Hindus. The loci are highly polymorphic in all sample populations studied. Except for D5S110, there is no evidence for departure from Hardy-Weinberg equilibrium (HWE) for the VNTR loci in the population groups. In addition, there is little evidence of correlation between the alleles at any of the pairs of loci and no evidence of association across the six loci. Finally, the data suggest that a multiple locus VNTR profile would be rare in the Punjabi or either of its subgroups.