Methods for the enhancement of fingermarks in blood

Fingermarks formed in or by blood often require specific development techniques. This review examines techniques and materials that may be used to enhance and record fingermarks deposited in blood or fingermarks generated by blood-contaminated papillary ridges. A large number of techniques are presented here and are discussed from a chemical as well as practical perspective. It is concluded that an optimized sequence of techniques targeting both latent (non-bloody) and bloody fingermarks must be applied to detect and enhance the maximum number of marks, and therefore optimize the information content from exhibits that may bear marks in blood.     

Micromethod for the detection of erythrocyte antigens in blood stains

A micromethod was developed to allow the analysis of blood stains of minor size by the absorption elution technique. The individual absorption, washing, and elution steps were carried out in Beckman tubes containing 5 microliter antiserum. The final agglutination reaction was read through the inverted microscope in microtest plates regularly used for HLA typing. For this final reaction, 2-4 microliter eluate was incubated with 2,000 red blood cells suspended in 1 microliter saline and supplement. For the purpose of standardization, the intensity of agglutination in the microtest plate had to be defined. In comparison to the standard method (tube test and centrifugation), the proposed method proved to be slightly more sensitive with regard to the Rhesus and slightly less sensitive with regard to the AB0 system. With the proposed method very small traces could be successfully analyzed. Thus, two cotton threads 1 mm in length were sufficient for testing antigens A and B, and two cotton threads 2.5 mm in length were enough to detect an Rh antigen.     

Development of an immunoassay for the differentiation of menstrual blood from peripheral blood

This study examined all unintentional firearm fatalities while hunting that occurred in Sweden between 1983 through 2008. The circumstances as well as the impact of the hunter's exam on fatality frequency were analysed. During these 26 years, there were 48 such fatalities, representing 53% of all (n=90) unintentional firearm deaths during the same period. The average annual number of fatalities decreased over the last few decades. Very restrictive firearm legislation in Sweden combined with the introduction of a mandatory hunter's exam since 1985 accounted, at least partly, for this finding. Moose hunting accounted for 46% of the fatalities and small game hunting for the remaining cases. The mean age of the victims was 50 years and 96% of them were males; all shooters were males. During moose hunting, most of the victims were mistaken for game, whereas in small game hunting most of the fatalities were related to falls and improper handling of the weapon. Human error was thus the main cause of these fatalities.     

A method for the determination of MN antigens in dried blood

MN phenotypes of experimentally prepared dried blood samples, some as old as six months, were obtained using sodium dodecyl sulfate polyacrylamide gels, electroblotting, and monoclonal antibodies.     

A simple spectrophotometric method for the determination of carboxyhemoglobin in blood

The spectrophotometric method for the determination of carboxyhemoglobin (HbCO) in blood reported by Fretwurst and Meinecke was modified so as to give the same values of percentage HbCO (HbCO%) as those determined by the oxygen electrode method. Values of HbCO% of nine practical samples determined by both the oxygen electrode method and the present method were nearly identical regardless of the presence of methemoglobin (Met-Hb) in blood. The present method is suitable for forensic practice.     

D-dimer assays for the identification of menstrual blood

A method to reliably distinguish menstrual blood from blood in the normal circulation (peripheral blood) would be of considerable use in the forensic analysis and interpretation of evidence in sexual offence investigations. Previous attempts to address this issue have explored microscopy, lactate dehydrogenase isozyme identification, mRNA and miRNA profiling, and identification of the products of fibrinolysis. Here, four assays for D-dimer, a terminal degradation product of fibrinolysis, are evaluated for their specificity and sensitivity in detection of menstrual blood. In addition the effect of exercise, and sample storage upon D-dimer detection was investigated. Comparison of different assays revealed significant differences in results given. Nevertheless, no positive results for D-dimer were obtained using peripheral blood, mixtures of peripheral blood with semen, or peripheral blood taken from donors after moderate exercise. D-dimer was found to be detectable in 100% of menstrual blood samples after 1 week at room temperature and also in samples stored long-term (>3 years) at -20 °C. D-dimer may be an effective, simple to use tool for the presumptive identification of menstrual blood identification.     

硫化氢中毒者血中硫化氢的检测及特征鉴别

目的探讨硫化氢(H2S)中毒者血中H2S的检测及特征鉴别;方法取新鲜空白血液和5℃下保存1月、1年的血液各2m L,经微波低火加热1min后,吸取顶空气体100μL进行GC/PFPD-S、GC/MS检测;取相同样本进行酸化处理后进行检测;取疑似为H2S中毒者血液直接加热后进行检测。结果新鲜血液和5℃下保存1月、1年的血液均可检出H2S成分,但保存1个月以上的血液可同时检出二硫化碳(CS2)成分;酸化处理后的血液,H2S和CS2成分检出的含量明显比未加酸化的血液高;中毒者血液中除了检出H2S成分外,还检出甲硫醚成分。结论血液样本同时检出H2S和较大量的CS2时,不宜判定为H2S中毒,提示可能为腐败所致,而同时检出H2S和较大量的甲硫醚,则可做出H2S中毒的判断。     

Comparison of the MTP immunoassay with EMIT in blood screening for drugs

We compared the MTP immunoassay with EMIT for the screening of drugs of abuse (opiates, cannabinoids, cocaine metabolites and amphetamines) in whole blood samples. These blood samples were obtained from the German police, when driving under the influence of drugs of abuse was suspected. For screening with the MTP immunoassay 25 microliters of serum or blood (without any pretreatment) was pipetted into the wells of the microtiter plates and the procedure was followed as described. Prior to screening with a Cobas Mira and EMIT reagents, the samples were treated with acetone to precipitate serum proteins. The cutoff for all drugs of abuse was set at 10 ng per ml of serum or blood. In most cases there was a good agreement between the negative and positive results of the two screening assays. The agreement between the two assays in the detection of opiates and cocaine was 91% and 93%, respectively, and for cannabinoids and amphetamines approximately 80%. The MTP immunoassay was more sensitive than EMIT for the detection of cannabinoids--but at the same time the MTP immunoassay was less specific. Both screening assays have a sensitivity of 100% for the detection of opiates and cocaine, but the specificity of the EMIT--also for opiates--was substantially lower. The MTP immunoassay has in respect to amphetamines a very high sensitivity, whereas the sensitivity of EMIT for amphetamines is inacceptable due to losses during sample preparation. The specificity of MTP immunoassay for amphetamines is not optimal, because a relatively large amount of samples tested false-positive for amphetamines at the cutoff of 10 ng/ml. In summary the MTP immunoassay, although not automated, performs well in comparison with EMIT, especially if the sample preparation for EMIT testing ist considered.     

A gas chromatographic method for detecting nitrites in the blood and stomach contents

Ethyl nitrite method is proposed as the tentative test for nitrites in studies of the blood and gastric contents. The sensitivity of the method in "pure" solutions is 17 micrograms/sample. The method is specific and its sensitivity is not inferior to routine chemical analyses of biological materials for nitrites.     

Comparison of morphological changes in white blood cells after death and in vitro storage of blood for the estimation of postmortem interval.

Estimation of the time of death is one of the most important problems for forensic medicine and law. Physical and chemical postmortem changes are evaluated together while estimating the time of death.In this study, in vitro storage and postmortem changes of white blood cells were aimed to be compared within the given postmortem interval, and a follow-up study was carried out. Blood smears which were obtained from 10 non-refrigerated cadavers (experimental group) and from 40 hospital patients (control group) have been evaluated to observe and compare changes during the in vitro storage and postmortem degenerative morphological changes that white blood cells undergo throughout the given postmortem intervals. The samples were examined by using a light microscope, and blood cells were differentiated by staining blood films with May-Grunwald stain, followed by Giemsa stain. Identifiable degenerated eosinophils and monocytes were first examined at 6h of death and the in vitro storage, and they were unidentifiable beyond 72 h of storage. Identifiable degeneration of neutrophils were first examined at 6h of death and storage while unidentifiable beyond 96 h of storage. Identifiable degeneration of lymphocytes were first examined at 24h of death, and they were still identifiable beyond 120 h.Cellular changes of leukocytes can be useful in the 6-120 h for estimating the time of in vitro storage, and the findings match during the first 21 h for both experimental and control groups. Finally, this follow-up study and the comparison will also be carried out for a longer postmortem interval, and other specific hypothesis that relate cellular changes in tissues other than blood with time since death are various points that needs to be studied.