The Effect of Household Oxidizing Cleaners on Chemiluminescence of Blood Using Bluestar®

This study tests the effect of three common oxidizing cleaners on the ability of the Bluestar Forensic® presumptive test for blood to identify the presence of blood on ceramic tile after cleaning. The cleaners tested were Lysol®, OxiClean®, and Arm & Hammer®. This study also tested which cleaner was the most effective at removing blood, measured by the intensity of chemiluminescence, which was quantified using RGB values in ImageJ. A “hasty” 1‐min cleaning of a blood droplet was simulated using the three cleaners. The chemiluminescence of the Bluestar® reactions after cleaning the blood‐treated region was compared to an untreated region of the same tile for each cleaner, as well as to the treated regions of tiles between the three cleaners. Results indicate that none of the three cleaners removed all of the blood (all p < 0.001) and that Lysol® removed more blood compared to the OxiClean® and Arm & Hammer®.     

Evaluation of six presumptive tests for blood, their specificity, sensitivity, and effect on high molecular-weight DNA

Luminol, leuchomalachite green, phenolphthalein, Hemastix, Hemident, and Bluestar are all used as presumptive tests for blood. In this study, the tests were subjected to dilute blood (from 1:10,000 to 1:10,000,000), many common household substance, and chemicals. Samples were tested for DNA to determine whether the presumptive tests damaged or destroyed DNA. The DNA loci tested were D2S1338 and D19S433. Leuchomalachite green had a sensitivity of 1:10,000, while the remaining tests were able to detect blood to a dilution of 1:100,000. Substances tested include saliva, semen, potato, tomato, tomato sauce, tomato sauce with meat, red onion, red kidney bean, horseradish, 0.1 M ascorbic acid, 5% bleach, 10% cupric sulfate, 10% ferric sulfate, and 10% nickel chloride. Of all the substances tested, not one of the household items reacted with every test; however, the chemicals did. DNA was recovered and amplified from luminol, phenolphthalein, Hemastix, and Bluestar, but not from leuchomalachite green or Hemident.     

Comparison of presumptive blood test kits including hexagon OBTI

Four presumptive blood tests, Hexagon OBTI, Hemastix(R), Leucomalachite green (LMG), and Kastle-Meyer (KM) were compared for their sensitivity in the identification of dried bloodstains. Stains of varying blood dilutions were subjected to each presumptive test and the results compared. The Hexagon OBTI buffer volume was also reduced to ascertain whether this increased the sensitivity of the kit. The study found that Hemastix(R) was the most sensitive test for trace blood detection. Only with the reduced buffer volume was the Hexagon OBTI kit as sensitive as the LMG and KM tests. However, the Hexagon OBTI kit has the advantage of being a primate specific blood detection kit. This study also investigated whether the OBTI buffer within the kit could be utilized for DNA profiling after presumptive testing. The results show that DNA profiles can be obtained from the Hexagon OBTI kit buffer directly.     

Cadmium-free quantum dots in aqueous solution: Potential for fingermark detection,synthesis and an application to the detection of fingermarks in blood on non-porous surfaces

The use of quantum dots (QDs) in the area of fingermark detection is currently receiving a lot of attention in the forensic literature. Most of the research efforts have been devoted to cadmium telluride (CdTe) quantum dots often applied as powders to the surfaces of interests.Both the use of cadmium and the nano size of these particles raise important issues in terms of health and safety. This paper proposes to replace CdTe QDs by zinc sulphide QDs doped with copper (ZnS:Cu) to address these issues. Zinc sulphide–copper doped QDs were successfully synthesized, characterized in terms of size and optical properties and optimized to be applied for the detection of impressions left in blood, where CdTe QDs proved to be efficient. Effectiveness of detection was assessed in comparison with CdTe QDs and Acid Yellow 7 (AY7, an effective blood reagent), using two series of depletive blood fingermarks from four donors prepared on four non-porous substrates, i.e. glass, transparent polypropylene, black polyethylene and aluminium foil. The marks were cut in half and processed separately with both reagents, leading to two comparison series (ZnS:Cu vs. CdTe, and ZnS:Cu vs. AY7). ZnS:Cu proved to be better than AY7 and at least as efficient as CdTe on most substrates. Consequently, copper-doped ZnS QDs constitute a valid substitute for cadmium-based QDs to detect blood marks on non-porous substrates and offer a safer alternative for routine use.     

Photoluminescence of blood by acidic hydrogen peroxide—A preliminary test

In this study, the authors found that treating blood with 1 M HCl and 2% (w/v) 5-sulfosalicylic acid (SSA) in 1% (v/v) hydrogen peroxide mixture can produce photoluminescence of blood. SSA was added as a blood fixer. The photoluminescence was induced by irradiation of a forensic light source at 505 nm, which was detected using a 550 nm barrier filter. In this experiment, various level of acid and hydrogen peroxide were tested to find the optimal formulation of reagents, spot tests were conducted with diluted blood to test the sensitivity of this reagent, and impressions in blood left on porous/nonporous surfaces were enhanced. The sensitivity of this solution was slightly lower than Bluestar and was similar to leucocrystal violet or leucomalachite green on both porous/non-porous surfaces. The photoluminescence of blood treated with this reagent has been observed over 2 months. Using this reagent, it was possible to observe fingermarks or footwear impressions in blood on a black porous/non-porous surface. Through this, it was found that using this reagent could enhance bloodstains regardless of the porosity or color of the surface.     

Effects of luminol on the subsequent analysis of bloodstains.

The effects of luminol upon additional presumptive chemical tests, subsequent confirmatory blood tests, species determination by immunoelectrophoresis, ABO typing by absorption elution, and genetic marker analysis by multienzyme system electrophoresis were examined. Results indicate that luminol does not affect additional presumptive chemical tests, confirmatory tests, species determination, or ABO typing, but does affect certain genetic marker systems.     

A preliminary investigation into the use of alginates for the lifting and enhancement of fingermarks in blood

Recent studies have reported the use of alginate in the lifting and subsequent enhancement of footwear marks in blood. A study was set up to assess the use of such a method in the treatment of fingermarks in blood on a variety of porous, non-porous and semi-porous surfaces. Other variables included ageing of the fingermarks in blood and the application of chemicals prior to or post-alginate lifting. All different variations were compared to direct chemical treatment of the substrate. The results demonstrated that alginate is not compatible with certain substrates (e.g. glass and tile). On substrates that were compatible with alginate (e.g. fabric and paper), the enhanced fingermarks on the alginate cast and the enhanced fingermarks on the post-alginate substrates appeared, overall, inferior compared to direct chemical enhancement without the use of alginate. A further variation using water-based protein stains directly mixed with the alginate appeared to provide enhancement directly on the substrate as well as simultaneous lifting and enhancing the fingermarks in blood on the alginate cast.     

Validation studies of rapid stain identification-blood (RSID-blood) kit in forensic caseworks

When bloodstains are detected at crime scene using presumptive tests (e.g. luminol, phenolphthalein, leuchomalachite green), it is important to establish the real human nature of each stain. This is possible using confirmatory tests. One of these is rapid stain identification-blood (RISD-blood) a lateral flow immuno-chromatographic strip test format which allows the identification of human blood by detection of glycophorin A, a red blood cell membrane antigen, using two anti-human glycophorin A (GPA) monoclonal antibodies.The aim of this study is to assess the sensitivity of RSID-blood test in old, degraded bloodstains and in some bloodstains previously treated with BlueStar Forensic, a presumptive test which is often used in crime scene investigations to detect latent bloodstains. The genetic analysis of all bloodstains of confirmed human nature was subsequently performed using the AmpF1STR Identifiler PCR Amplification Kit (Applied Biosystems), to validate the possibility of obtain a consistent and reliable DNA typing results.     

Evaluation of a Visualization Assay for Blood on Forensic Evidence

In forensics, bloodstains on dark fabrics might be invisible for the naked eye. Although several visualization, presumptive, and confirmatory blood tests have been developed, all have one or more disadvantages, especially on DNA analysis. We report here the use of a visualization assay that can visually detect blood drops up to 1/20 dilution. In this assay, the fabric is placed between two wet filter papers and covered by glass surfaces on both sides. Pressure is applied on the glass surfaces in which bloodstains transfer onto the filter papers through capillary forces. Detected stains can be tested with other more sensitive presumptive blood tests performed on the filter paper. Even more, DNA analysis can be performed on the transferred bloodstains. The presented visualization assay is easy to perform, extremely cheap, requires little hands on time, and does not affect bloodstain pattern analysis.     

A comprehensive study into false positive rates for ‘other’ biological samples using common presumptive testing methods

The identification of biological fluids or materials in forensic samples is a key requirement in forensic science that relies on chemical and biological based tests, most of which exhibit false positivity. When reporting results from such tests, Forensic Scientists use words such as probable, possible, and likely, without always being able to provide robust support for these conclusions. In collating information about false positive rates for a number of these tests, we found limited research into the cross reactions observed from ‘other’ biological samples in commonly encountered case sample stains. By ‘other’ we mean biological fluids or materials that are not the primary target of the presumptive test being used. Here we carry out a specificity study to fill gaps in the literature for a number of the presumptive chemical, biological and immunochromatographic tests used to presumptively screen for blood, semen and saliva. The tests selected for this study are the widely used tests: Luminol, TMB/Combur³ Test® E, Kastle-Meyer (KM), RSID™ - Blood, ABAcard® HemaTrace®, Acid Phosphatase (AP), ABAcard® p30, RSID™ - Semen, Phadebas® ‘Tube’ Test, Phadebas® ‘Press’ Test, and RSID™ - Saliva tests. Specificity for each of these was tested in known samples, from volunteers, of blood, semen, saliva, urine, sweat, vaginal material, faeces and breast milk, and then false positive rates were determined.     

“502”胶液体显现潜手印技术的研究

目的研究探索"502"胶溶液显现手印的方法.方法以石油醚为分散剂,添加对苯二酚作为显现增强剂,配制"502"胶显现液.结果能够显现非渗透客体上油质加、减层手印、加减层混合手印及普通汗潜手印,其显现效果与"502"胶熏显法非常相似.结论该方法具有方便、快捷、灵敏等特点,是"502"胶显现手印技术的重要补充.     

In depth investigation of the capabilities and limitations of combined proteomic-MALDI MS based approach for the forensic detection of blood

For the past 7 years, Matrix Assisted Laser Desorption Ionisation Mass Spectrometry (MALDI MS) based methods have been developed and published for the forensic detection of blood in stains and fingermarks. However, in the view of adoption in an operational context, further investigation into the capabilities and limitations of this approach must be conducted. The refinement and testing of this approach must also be tailored to the requirements of the end users, enabling them to address the specific circumstances most encountered in a forensic scenario. The present study delves deeper into the assessment of the applicability of MALDI MS based strategy for the reliable and robust detection of human blood through: (i) a semi-qualitative assessment of the sensitivity of the method, (ii) a wider investigation of the compatibility of the method with the prior application of commonly used presumptive tests and (iii) assessment of the specificity of the method (when blood is present in mixture with other biofluids) and of its robustness, by assessing blood detection from a range of porous materials. The findings strengthen the evidence supporting the adoption of MALDI MS based approaches as a confirmatory test for the forensic detection of human blood in an operational context.     

The Influence of Selected Fingerprint Enhancement Techniques on Forensic DNA Typing of Epithelial Cells Deposited on Porous Surfaces

Fingerprints deposited at crime scene can be a source of DNA. Previous reports on the effects of fingerprint enhancement methods have focused mainly on fingermarks deposited in blood or saliva. Here, we evaluate the effects of fingerprint enhancement methods on fingerprints deposited on porous surfaces. We performed real‐time quantification and STR typing, the results of which indicated that two methods (iodine fuming and 1,2‐indanedione in ethyl acetate enhancement) had no effect on the quantity of DNA isolated and resultant STR alleles when compared to control samples. DNA quantities and allele numbers were lower for samples enhanced with silver nitrate and 1,2‐indanedione in acetic acid when compared to control samples. Based on DNA quantity, quality, and observable stochastic effects, our data indicated that iodine fuming and 1,2‐indanedione in ethyl acetate were the preferred options for the enhancement of fingerprints on porous surfaces.     

新型荧光502粉末与502胶＋荧光染色显现潜在手印的比较

目的对新型荧光502粉末显现非渗透性光滑客体表面潜手印的一步荧光502显现新技术和传统502胶水熏显＋荧光染料染色显现手印技术进行比较研究。方法比较实验研究,对荧光502粉末和502胶水使用同一自动熏显柜先后进行熏显,荧光502粉末熏显结束后直接在蓝光灯下激发进行观察和拍照;502胶水在熏显完成和聚合物完全固化后使用罗丹明6G和BBD溶液进行荧光染色,再进行光致荧光照相。结果一步熏显和二次染色的显现效果基本相同,但两者的显现效果也因检材性质和遗留时间的不同而存在一些差别。结论新型荧光502粉末可以作为一种显现非渗透性光滑客体表面上潜手印的常用方法,尽管新方法对某些客体的显现效果并不好,但对大多数客体来说,其显现效果并不弱于二次染色的方法,并且使用新型荧光502粉末进行一步熏显不会引入有机溶剂,不会引起502聚合物的溶解或造成破坏,确保了纹线及其细节特征不被损坏,也避免了染色后因漂洗不当使手印纹线被冲掉的可能,还不会破坏脱落细胞等生物检材。     

Fingermark detection on non-porous and semi-porous surfaces using YVO4:Er,Yb luminescent upconverting particles

This article describes the use of an anti-Stokes luminescent material (upconverter), yttrium vanadate doped with ytterbium and erbium (YVO(4):Er,Yb), for the development of latent fingermarks on a range of non-porous surfaces. Anti-Stokes luminescent materials emit light at shorter wavelengths than the excitation wavelength. This property is unusual in both natural and artificial materials commonly found as exhibits in forensic science casework. As a result, fingermark detection techniques based on anti-Stokes luminescence are potentially extremely sensitive and selective. Latent fingermarks on non-luminescent and inherently luminescent substrates, including Australian polymer banknotes (a well-known 'difficult' surface), were developed with YVO(4):Er,Yb by dry powder and wet powder techniques. The effectiveness of YVO(4):Er,Yb for fingermark detection was compared with that of cyanoacrylate fuming and of sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF(4):Er,Yb). The results illustrate some benefit of luminescent up-converting phosphors over traditional luminescence techniques for the detection of latent fingermarks.     

A comparison of the use of vacuum metal deposition versus cyanoacrylate fuming for visualisation of fingermarks and grab impressions on fabrics

Both vacuum metal deposition (VMD) and cyanoacrylate fuming (CAF) are techniques used to visualise latent fingermarks on smooth non-porous surfaces such as plastic and glass. VMD was initially investigated in the 1970s as to its effectiveness for visualising prints on fabrics, but was abandoned when radioactive sulphur dioxide was found to be more effective. However, interest in VMD was resurrected in the 1990s when CAF was also used routinely. We now report on studies to determine whether VMD or CAF is the more effective technique for the detection of marks on fabrics. Four different fabrics, nylon, polyester, polycotton and cotton, were utilised during this study, along with 15 donors who ranged in their age and ability to leave fingermarks, from good to medium to poor, thus reflecting the general population. Once samples were collected they were kept for a determined time (1, 2, 3, 4, 5, 6, 7, 14, 21 or 28 days) and then treated using either the gold and zinc metal VMD process or standard cyanoacrylate fuming.The smoother fabrics, such as nylon, consistently produced greater ridge detail whereas duller fabrics, like cotton tended only to show empty prints and impressions of where the fabric had been touched, rather than any ridge details. The majority of fabrics did however allow the development of touch marks that could be targeted for DNA taping which potentially could lead to a DNA profile. Of the two techniques VMD was around 5 times more effective than CAF, producing a greater amount of ridge detail, palmar flexion creases and target areas on more samples and fabrics.     

The analysis of biological samples from crime scene for a future human DNA profile confrontation. Effects of presumptive test reagents on the ability to obtain STR profiles for human identification

Because of the increase of evidence of blood stains, that have been washed or cleaned in an attempt to mask the analysis of DNA profiles, there is also an increase in the use of presumptive tests on samples sent to laboratories. Some of the presumptive tests, used to identify blood and semen stains, could potentially affect the recovery of high molecular weight DNA from the samples, or extinguish them, especially those already present in small quantities. After the presumptive tests, often these samples are discarded. This study aimed to examine the possibility of obtaining a DNA profile from samples submitted for presumptive testing and cleaned with bleaches with and without chlorine. Two different protocols were conducted: (a) A unique sample of human blood in natura (5 μL), already typed through the DNA techniques with the genetic profile previously known (control), was distributed onto cotton fabrics and dried at room temperature. Four samples of fabric were macerated in saline solution and Coombs serum and then stored for three months (room temperature and freezer −20 °C). (b) Another sample of human blood, type A, in natura, already typed through the techniques of DNA (control) was used. Aliquots of 200 μL were distributed in: cotton, denim and synthetic fabric. The samples were dried at room temperature for 24 h. The blood stains in those fabrics (cotton, denim and synthetic) were then divided into three groups: unwashed, cleaned with chlorine bleach and cleaned with chlorine bleach and soap powder. The samples were again dried at room temperature for 24 h, before the use of luminol. The DNA were extracted with Chelex 100 and amplified with the Identifiler Kit (Applied Biosystems). The blood stains exposed to saline and Coombs serum had DNA profiles consistent with untreated samples (controls). This result shows that the experts should keep and store the samples treated with saline and Coombs serum for future DNA confrontation when necessary. Also discussed in this paper the pattern of blood stains after washing with bleaching solutions, as well as the quantity of DNA obtained from these samples.     

Location of Artifacts Deposited by the Blow Fly Lucilia cuprina After Feeding on Human Blood at Simulated Indoor Crime Scenes

Human DNA profiles can be obtained from fly artifacts (feces and regurgitant) when a fly has been feeding on biological material, sometimes 2 years after deposition. Morphological similarity between artifacts and spots of unaltered biological material make it difficult to distinguish between them, and presumptive and confirmatory forensic tests are unreliable in making the distinction. Knowing possible artifact locations will assist investigators in recognizing where DNA contamination might occur. Flies were released into a house with human blood available under a variety of different climatic and lighting conditions. The location of flies and artifacts was recorded after 72 h. It was found flies may move toward warm or well‐lit areas and deposit artifacts there, but artifacts were predominantly located around food sources and were often found in low positions. Factors such as ambient temperature, and the proximity of light and food sources, had an impact on where artifacts were deposited.     

The effect of luminol on presumptive tests and DNA analysis using the polymerase chain reaction.

This study was designed to test the following factors involved with processing luminol treated bloodstained evidence: 1) The reactivity of other presumptive chemical color tests, phenolphthalin (PT) and tetramethylbenzidine (TMB), following the application of the light emitting luminol presumptive test. 2) The effect of different cleanings of various bloody substrates on the luminol test. 3) The effect of different cleanings of various bloody substrates on the ability to obtain DNA suitable for PCR testing. 4) The ability to extract DNA from luminol treated bloodstained substrates using three extraction techniques. 5) The effect of spraying washed and unwashed bloodstains on various substrates with luminol on the ability to correctly type the DNA using PCR. Our findings indicated that luminol did not adversely effect the PCR testing and did not interfere with the PT and TMB presumptive tests for blood. It was determined that the substrate and the method of cleaning were the major factors affecting DNA yield and the ability to type the bloodstains using PCR based technologies.     

The recovery of latent text from thermal paper using a simple iodine treatment procedure

Faded, or actively removed text on thermally printed paper samples may be enhanced and retrieved through the use of a simple iodine fuming procedure. The recovery of printed documentation evidence in this fashion is neither affected by prior fingerprint enhancement techniques (such as ninhydrin or DFO), nor by sample age. This method allows, for the first time, evidence to be obtained from completely faded thermal paper samples (receipts, for example) as well as allowing deliberately removed printed text (a consequence of solvent washing pre-treatment in latent fingerprint enhancement procedures) to be recovered.