Examination of the correlation of groupings in blood and semen

The grouping of blood/saliva samples from a male so as to predict his semen groups is only justified if there is a strict correlation between the groupings in these body fluids. This correlation has been examined in the ABO, phosphoglucomutase (PGM1) and glyoxalase I (GLO) grouping systems in blood and semen samples collected from more than 250 individuals. Though no results proved inconsistent with this correlation, a number of semen gave inconclusive grouping results. Reasons for this are discussed as well as the relevance of the results to semen stain analysis. Semen amylase activities are also reported.     

Electrophoretic typing of glyoxalase I (GLO I) isoenzymes using a mixed starch/agarose gel

A technique was developed to type the glyoxalase I (GLO I) isoenzymes using a mixed agarose/starch gel. Over six hundred blood samples from Caucasoid people living in separate regions of South Australia were examined and the results compared with other Caucasoid population surveys. Paired blood and semen samples were also tested and the limitations of the technique with regard to blood and semen stains analysis was evaluated.     

Criminalistics: An introduction to forensic science (2nd edition): By Richard Saferstein. Publisher: Prentice-Hall Inc., Englewood Cliffs,New Jersey,U.S.A., 1981, pp. 470, price $18.95 (cloth)

A technique was developed to type the glyoxalase I (GLO I) isoenzymes using a mixed agarose/starch gel. Over six hundred blood samples from Caucasoid people living in separate regions of South Australia were examined and the results compared with other Caucasoid population surveys. Paired blood and semen samples were also tested and the limitations of the technique with regard to blood and semen stains analysis was evaluated.     

用酶标抗体免疫组化法测定性交后阴道内容物中精子的ABO血型

应用间接酶标抗体免疫组化法测出了53例新鲜精液、5例陈旧精斑及40例阴道分泌液中的精子与阴道脱落上皮细胞的ABO血型,30例精子与不同血型分泌型阴道分泌液孵育,未发现精子吸附阴道液中血型物质的现象,同时发现人类睾丸曲精细管中部份生精细胞、精子细胞,精子;直细精管部份上皮细胞、精液、精子;睾丸网大部份上皮细胞及副睾管中的精液与精子均含ABH抗原,故认为精子上的ABH抗原主要是精子固有抗原,13例性交后阴道内容物中精子的ABO型测定结果:7例与供者血型吻合,6例不吻合。6例中5例从O型精子中测出了女方分泌型阴道分泌液中的A或AB物质,1例B型精子未测出B及H抗原,文中对这种现象进行了讨论。     

Polymorphism of isoenzymes in preserved muscle tissues

In muscles preserved in formalin enzymes were not found to be active. In muscles treated by ethanol the ESD, GLO, GPT and PGP enzymes were active. The best results were obtained in the case of acetone treatment. The phenotypes ESD, GLO, GPT and PGP in tissues corresponded with the ones in the comparative blood samples.     

A sandwich enzyme-linked immunosorbent assay for ABO blood typing of semen by using anti-p 84 monoclonal antibody as a marker of blood group substance in semen

A blood group substance (BGS), a protein with ABH antigenic activity, was isolated from human seminal plasma and designated as p 84 (Sato, 1995). We have developed a method for determining the ABO blood type of semen by performing a sandwich enzyme-linked immunosorbent assay (ELISA) in which p 84 is captured with an anti-p 84 monoclonal antibody, and evaluated the specificity and sensitivity of this method. Although BGS activity was detected in semen sensitively by this method, it was not detected in saliva, urine, breast milk, blood or vaginal secretions. Since the concentration of p 84 in semen was independent of the secretion status, the status can be determined as non-secretor when p 84 but not BGS activity was detected. To determine the stability of BGS activity on p 84, dried stains of semen on filter paper were kept at 4, 26, and 37 degrees C for 8 months, 2 years and 1 month, respectively, and their BGS activities were examined. After 8 months at 4 degrees C, over 60% of the original BGS activity was recovered from the stain. The activity could be detected even from a square as small as 0.25 by 0.25 cm. After 1 month at 37 degrees C and 2 years at 26 degrees C, 31 and 20% of the BGS activity, respectively, still remained. It could be detected from the pieces of 1.0 by 1.0 cm and 0.5 by 0.5 cm squares, kept for 1 month at 37 degrees C and 2 years at 26 degrees C, respectively. Finally, semen was mixed with saliva or blood at varying volumetric ratios and used for the sources of dried stains. The BGS activity of p 84 could be detected in the stains until the ratio between semen and saliva or blood reached 1:4. We conclude that this sandwich ELISA offers a more sensitive and specific method for determining the ABO blood type of semen samples obtained from sexual assault victims than existing methods, such as the conventional absorption-elution and classical hemagglutination-inhibition tests.     

microRNA Detection in Blood,Urine, Semen,and Saliva Stains After Compromising Treatments

Evaluation of microRNA (miRNA) expression as a potential method for forensic body fluid identification has been the subject of investigation over the past several years. Because of their size and encapsulation within proteins and lipids, miRNAs are inherently less susceptible to degradation than other RNAs. In this work, blood, urine, semen, and saliva were exposed to environmental and chemical conditions mimicking sample compromise at the crime scene. For many treated samples, including 100% of blood samples, miRNAs remained detectable, comparable to the untreated control. Sample degradation varied by body fluid and treatment, with blood remarkably resistant, while semen and saliva are more susceptible to environmental insult. Body fluid identification using relative miRNA expression of blood and semen of the exposed samples was 100% and 94%, respectively. Given the overall robust results herein, the case is strengthened for the use of miRNAs as a molecular method for body fluid identification.     

Blood group frequencies of the population of Trinidad and Tobago, West Indies.

The results of grouping tests performed on blood samples collected over a five-year period at the Trinidad and Tobago Forensic Science Centre are presented. The samples were tested using the ABO, PGM, EAP and GLO blood group systems. Phenotypic frequencies and allele frequencies for each system were calculated for the two major ethnic groups of the population, the African and East Indian. Matching probabilities, which can be used in the interpretation of physical evidence in forensic cases, were also calculated.     

Vaginal swabs: endogenous and postcoital components

The relationship between components found on vaginal swabs was examined to determine whether the presence and quantity of a particular component could be used to predict the presence of others or to help interpret grouping results. Vaginal swabs were tested for the presence of blood, cellular material, spermatozoa, acid phosphatase, p30, ABH, Lewis, EsD, GLO I, PGM and PGM subtype. Methods included rocket electrophoresis and p-nitrophenyl phosphate assay for acid phosphatase; rocket and cross-over electrophoresis for p30. Results from 323 semen-free and postcoital vaginal swabs from known donors are presented. Comparison of methods showed that seminal acid phosphatase and p30 were detected more often by the rocket techniques. Attributing the grouping results to semen, based on the reactivity of any single component, could lead to erroneous conclusions. Activation of vaginal components in the presence of semen and endogenous vaginal levels are discussed.     

Development of a Real‐Time PCR‐Based Method for Analyzing Semen‐Specific Unmethylated DNA Regions and Methylation Status in Aged Body Fluid Stains

The detection of semen in forensic investigation is considered important evidence of sexual assault. In this study, we report the development of a real‐time polymerase chain reaction‐based method for identifying semen that can simply and rapidly analyze the semen‐specific unmethylated region of the DACT1 gene. Using two fluorescent probes designed for the methylated or unmethylated status, this method could perform quantitative analysis of the methylation status in this region. Furthermore, this method was used to analyze various body fluid samples, including 29‐year‐old semen and blood stains. The results showed that this method can detect almost exclusively semen or nonsemen signals even in highly decomposed samples, while a few semen or nonsemen samples showed slight signals of the other fluorescence probe. Although there is still a need for further analysis such as setting thresholds to analyze unknown samples, this method could be a useful supplementary tool for identifying semen, especially in old stains such as those in cold‐case investigations.     

Transferrin (TF) typing from semen stains using isoelectric focusing and immunoblotting: correlation of TF types among blood, semen, urine, and vaginal secretion.

We describe a method for obtaining nondistorted and reproducible transferrin (TF) typing from liquid semen and semen stains. Isoelectric focusing of TF isoproteins on polyacrylamide gel (IEF-PAGE, pH 4 to 6.5) was accomplished using a 0.5 mm thick gel. The separated isoproteins were then visualized by immunoblotting with TF-specific antibody. Pretreatment of semen samples with neuraminidase enhanced the TF band resolution. The method was reliable, sensitive and simple, with a high resolution. When maintained at room temperature, laboratory-prepared semen stains were TF-typable for up to at least 50 weeks. The TF types in semen stains were correlated with the types found in the corresponding blood and urine samples. TF typing could therefore provide an additional discriminant characteristic in the forensic examination of semen stains. An evaluation of TF typing by IEF-PAGE and immunoblotting was also performed on casework samples submitted to our laboratory.     

Assessment of body fluid identification and DNA profiling after exposure to tropical weather conditions

Despite current advances in body fluid identification, there are few studies evaluating the effect of environmental conditions. The present work assessed the detection of body fluids, blood, semen, and saliva, through lateral flow immunochromatographic (LFI) tests, exposed to tropical weather conditions over time, also evaluating the possibility of obtaining STR (short tandem repeat) profiles and identifying mitochondrial DNA (mtDNA) polymorphisms. Blood, semen, saliva samples, and mixtures of these fluids were deposited on polyester clothes and exposed to open-air tropical weather conditions for 1 month. The test versions from LFI (SERATEC®, Germany) Lab and crime scene (CS) used for the detection – one per each body fluid type – demonstrated that it is possible to identify body fluids and their mixtures up to 14 days after deposition. At 30 days, blood and semen were detected but not saliva. Full STR profiles were obtained from 14-day-old blood samples, and partial profiles were obtained from the remaining samples. It was possible to sequence mtDNA in the samples previously analyzed for STR profiling, and haplogroups could be assigned. In conclusion, this study demonstrated for the first time the possibility of body fluid identification and DNA profiling after exposure to tropical weather conditions for 1 month and also demonstrated the value of mtDNA analysis for compromised biological evidence.     

Transferrin subtyping of bloodstains and semen using isoelectric focusing and immunoblotting.

Transferrin (TF) subtyping was carried out on bloodstains that had been made on cotton sheeting and stored under a variety of conditions ranging from -20 degrees C to +37 degrees C. The time limit of detection was longer than 54 weeks after dry storage under each condition. Moreover the correlation between isoprotein types of the TF in blood and semen samples from the same individual was determined in 103 men. All three TF common types and two rare types in all semen samples correlated with the type found in the corresponding blood sample. A combination of isoelectric focusing separation and immuno-enzyme-linked detection may prove to be very useful for forensic TF subtyping.     

Transferrin subtyping of bloodstains and semen using isoelectric focusing and immunoblotting

Transferrin (TF) subtyping was carried out on bloodstains that had been made on cotton sheeting and stored under a variety of conditions ranging from −20°C to +37°C. The time limit of detection was longer than 54 weeks after dry storage under each condition. Moreover the correlation between isoprotein types of the TF in blood and semen samples from the same individual was determined in 103 men. All three TF common types and two rare types in all semen samples correlated with the type found in the corresponding blood sample. A combination of isoelectric focusing separation and immuno-enzyme-linked detection may prove to be very useful for forensic TF subtyping.     

PCR－RFLP技术鉴定ABO基因型的法医学应用研究

目的建立PCR－RFLP、非变性PAG胶垂直电泳和银染技术进行ABO基因分型的方法体系,并对200名广东汉族人群ABO基因型频率进行了调查。方法用Chelex－100和酚、氯仿抽提法处理样本,PCR扩增后用非变性聚丙烯酰胺凝胶垂直电泳和银染技术检测分型。结果ABO位点特异性扩增片段长度为175bp～210bp,6种基因型频率分布为0.0250～0.4300,杂合度H值为0.5162,个体识别力DP值为0.7111。结论该方法可成功运用于血液、血痕、精斑、毛发、骨组织和混合斑等检材的个体识别及亲权鉴定的检验。     

2例亲权鉴定案中的嵌合体STR谱分析

先天性基因嵌合体由遗传获得，是胚胎早期两个不同受精卵相互混合或血管交叉吻合继而发育成的一个包含两套（种）不同细胞系的个体。分为血型嵌合体（twin chimeras）和全身器官组织嵌合体（whole body chimerasl两种。本文通过两例亲权鉴定中发现的男性先天性嵌合体及其家族成员常染色体、性染色体的STR谱遗传分析，探讨先天性基因嵌合体的类型、发生、基因嵌合现象在不同组织中的表现及其作为证据可能在法庭科学调查中存在的风险。分析结果表明，两例男性Y—STR单倍型显示正常，分别与其男性家族成员Y—STR单倍型一致。但其在常染色体和X染色体上的STR基因表现嵌合现象，分别是在胚胎发育早期由男性-女性、男性-男性的异卵双生子发生融合并发育而成的的全身器官组织嵌合体。嵌合体上不同来源组织的STR等位基因强度显示不均衡状态。     

精斑中磷酸葡萄糖变位酶(PGM_1)及其亚型的电泳分型

本文用淀粉凝胶电泳法和 PAGIEF 对精斑 PGM_1普通型及亚型进行了检测。169份精液斑的 PGM_1分型结果是:PGM_1 1—1 87例;PGM_1 2—1 66例;PGM_1 2—2 16例,其中31例同一个体红细胞及精液 PGM_1分型的结果完全一致。研究了138例不同精子数精斑的 PGM_1型,发现精子数的多少对分型无影响。亚型检测结果与红细胞一样可分10型。     

Analysis of body fluid mixtures by mtDNA sequencing: An inter-laboratory study of the GEP-ISFG working group

The mitochondrial DNA (mtDNA) working group of the GEP-ISFG (Spanish and Portuguese Group of the International Society for Forensic Genetics) carried out an inter-laboratory exercise consisting of the analysis of mtDNA sequencing patterns in mixed stains (saliva/semen and blood/semen). Mixtures were prepared with saliva or blood from a female donor and three different semen dilutions (pure, 1:10 and 1:20) in order to simulate forensic casework. All labs extracted the DNA by preferential lysis and amplified and sequenced the first mtDNA hypervariable region (HVS-I). Autosomal and Y-STR markers were also analysed in order to compare nuclear and mitochondrial results from the same DNA extracts. A mixed stain prepared using semen from a vasectomized individual was also analysed. The results were reasonably consistent among labs for the first fractions but not for the second ones, for which some laboratories reported contamination problems. In the first fractions, both the female and male haplotypes were generally detected in those samples prepared with undiluted semen. In contrast, most of the mixtures prepared with diluted semen only yielded the female haplotype, suggesting that the mtDNA copy number per cell is smaller in semen than in saliva or blood. Although the detection level of the male component decreased in accordance with the degree of semen dilution, it was found that the loss of signal was not consistently uniform throughout each electropherogram. Moreover, differences between mixtures prepared from different donors and different body fluids were also observed. We conclude that the particular characteristics of each mixed stain can deeply influence the interpretation of the mtDNA evidence in forensic mixtures (leading in some cases to false exclusions). In this sense, the implementation of preliminary tests with the aim of identifying the fluids involved in the mixture is an essential tool. In addition, in order to prevent incorrect conclusions in the interpretation of electropherograms we strongly recommend: (i) the use of additional sequencing primers to confirm the sequencing results and (ii) interpreting the results to the light of the phylogenetic perspective.     

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.