This application claims the benefit of U. Provisional Application No. The field of the disclosure relates generally to dating biological samples through the use of fluorescence. Throughout history, bloodstain dating has played a significant role in areas such as criminal justice. Numerous violent crimes have remained unsolved for lack of evidence and the incapability to assign timing of bloodstains and other bodily fluids, thereby placing victims and potential defendants at the scene of the crime during the period at issue. Particularly, in the last two hundred years, criminal investigators explored a variety of approaches to establish a reliable quantitative method, from the evaluation of bloodstain color as shown in total organic carbon TOC analysis, microscopic analysis of red corpuscles and a water solubility scale in the middle of the 19th century, to electrochemistry, electron paramagnetic resonance, atomic force microscopy, polymer chain reaction, and optical spectroscopy in the 21 st century. Accordingly, there is a need in the art for an accurate method of determining blood age. It would further be advantageous if this method could be used to determine the age of various biological samples. The present disclosure generally relates to a method for dating biological samples such as bloodstains based on the fluorescence lifetime of the sample. In some embodiments, the fluorescence lifetime value of a biological sample is determined through the detection of a conformational change of one more of a protein and an endogenous fluorophore.
WO2017020000A1 – Spectroscopic methods for body fluid age determination – Google Patents
The present invention relates to an apparatus and method for dating a body sample, preferably, but not exclusively, a sample of body fluid, such as blood, which may be external to the body, for example, having caused stains on an external substrate, such as a floor, wall, etc. It is well known that dating of both external blood stains and internal bruising is a useful forensic technique to determine when a particular injury was caused to a person.
In the one case, the injury would have been such that the skin was punctured and blood was spilt and in the other case no blood was spilt externally, but bruising, to a greater or lesser extent was caused.
In May, a young woman was found severely injured in the Eltham district of London, her head brutally smashed with a plaster’s hammer.
Chemists in the US have developed a quick and simple way to find out how old bloodstains are using natural fluorescence measurements. Knowing when blood has been spilled can help forensic scientists pinpoint when a crime took place, but current techniques – such as optical measurements of haemoglobin degradation – can be unreliable. Now, Mikhail Berezin and colleagues at Washington University in St Louis, US, have developed a technique that relies on the fluorescence lifetime of the tryptophan in blood proteins.
As the environment changes and the proteins age, the fluorescence lifetime decreases. Tryptophan residues in proteins found in blood could be used to date bloodstains at crime scenes.
A Raman “spectroscopic clock” for bloodstain age determination: the first week after deposition
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The novel retinal imaging modality known as fluorescence lifetime imaging ophthalmoscopy Dating bloodstains with fluorescence lifetime measurements.
Raman spectroscopy and advanced statistics allow the researchers to date a blood stain accurately, provided said blood stain is less than two years old. Raman spectroscopy involves shining a laser on a sample and measuring the intensity of scattered light. No two substances give the exact same Raman spectrum and so the spectrum is essentially a unique fingerprint for a given material.
In a proof of principle, Lednev’s team had collected fresh blood two years ago at the start of their experiments from two healthy adults a man and a woman. They dried the samples to simulate a crime scene blood residue and then analyzed the samples at 15 different times over the two-year period. At the moment, crime scene investigators have no single validated approach to determine when a blood stain might have been deposited, which could, in theory, lock down a case or exclude a suspect.
The team hopes to ultimately develop a “point and shoot” Raman spectroscopy instrument that could be used by law enforcement officers at a crime scene to quickly analyze a whole range of biological stains and deposits. As the environment changes and the proteins age, the fluorescence lifetime decreases. Tryptophan residues in proteins found in blood could be used to date bloodstains at crime scenes. But then a new type of laser became available, with a wavelength of nm.
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as soon as possible. Download date: different groups of bloodstains were measured using visible reflectance spectroscopy. reflectance, fluorescence or Raman spectroscopy, have the potential to allow on field exponential decay is observed for blood stains with ages between 1 and 20 days, again in.
Provisional Patent Application Serial. Department of Justice I. The government has certain rights in this invention. Especially in cases of violent crimes, such as assaults, murders, or homicides, blood can provide investigators with very critical information Castro et al. Knowing the age, or time since deposition TSD , of a bloodstain can assist investigations in at least two ways: it can establish when a crime occurred, and it can discriminate bloodstains that relate to the crime from those that are extraneous.
Primarily for these reasons, it has been a major goal in the field to establish a technique for determining the TSD of bloodstains accurately Bremmer et al. Forensic Sci. Part 3 : Visualizing Blood on Fabrics,” Anal. Immunoassay 10 4 ; U. Patent No. In a review article of forensic body fluid testing, Virkler et al. While it is preferable to conclusively identify a stain as blood before DNA testing, this is almost never done in practice due to the lack of time and money Kobilinsky, L.
WO2009130580A1 – Apparatus and method for dating a body sample – Google Patents
In summary, fluorescence lifetime was shown to be a promising technique to evaluate the age of a bloodstain in a crime scene within the first week. The method is fast ca. The major improvement of the technique will come from the development of the lifetime imaging technique, in which the average fluorescence lifetime is evaluated across the region of interest in the bloodstain. Such an approach will minimize the problems with sampling and provide more accurate results. The measurements can potentially be performed in solid state by using a handheld fluorescence-lifetime instrument, which could be applied to the bloodstain directly at the crime scene with no additional sample handling.
Dating bloodstains with fluorescence lifetime measurements. Authors: Kevin Guo Near-infrared fluorescence lifetime pH-sensitive probes. Authors: Mikhail Y.
Augmented longitudinal acoustic trap for scalable microparticle enrichment, Biomicrofluidics , , 12, Zhegalova NG, Gonzales G. Two-photon optical properties of near-infrared dyes at 1. Achilefu S. Multimodality imaging of gene transfer using a receptor-based reporter gene, J. Multiphoton microscopy of near-infrared contrast agents, J. Near- infrared fluorescent and magnetic resonance imaging molecular probe with high T 1 relaxivity for in vivo multimodal imaging.
Fluorescence lifetime measurements and biological imaging, Chem. Radioactivity synchronized fluorescence enhancement using a radionuclide fluorescence-quenched dye J. Featured in Science: J.
Dating bloodstains with fluorescence lifetime measurements.
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“Dating bloodstains with fluorescence lifetime measurements. On Measuring the Volume of very small Drops of Blood and Correlation of this.
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Date of publication April 16, ; date of current age of bloodstains by enzyme activities in blood cells in  Using ratios of S. Mc Shine et al. applied fluorescence lifetime to determine the time since the plane mirrors and finally focused on the sample surface by a convex lens with a focal length of. mm.
This statement outweighed the other evidence, the man was sent free, and the crime known as the Eltham murder remains a mystery. These two examples illustrate the important role of bloodstain dating in criminal justice. In the last two hundred years, criminal investigators explored a variety of approaches to establish a reliable quantitative method, from the evaluation of bloodstain colour as shown in TOC, microscopic analysis of red corpuscles and a water solubility scale in the middle of the 19th century [ 3 ] , to electrochemistry [ 4 ] , electron paramagnetic resonance [ 5 ] , atomic force microscopy [ 6 ] , polymer chain reaction [ 7 ] , and optical spectroscopy [ 8 ] in the 21st century.
Herein, we demonstrate a novel method for bloodstain dating based on the fluorescence lifetime of blood. We show that the intrinsic fluorescence lifetime quickly and reliably reports the blood age. In May , a young woman was found severely injured in the Eltham district of London, her head brutally smashed with a plaster’s hammer. Our approach is based on a fact that the fluorescence lifetime of tryptophan — the major endogenous fluorophore in blood proteins – is highly sensitive to the protein conformation [ 12 , 13 ].
Consequently, we expected that the time-related degradation of proteins in blood would reflect the blood age. To verify our hypothesis, we plated fresh blood from different dogs onto plastic Petri dishes. The blood was left exposed to room air and at certain time points, the bloodstain was scraped and dissolved in PBS buffer for lifetime measurements. Each measurement was conducted from three different scratches of blood obtained from four different dogs.
For fluorescence lifetime measurements, we utilized a nm subnanosecond pulsed LED in conjunction with the time-resolved single photon counting TCSPC technique. Shorter wavelengths potentially excite tyrosine residues leading to energy transfer to tryptophan, while longer wavelengths excite NAD P H and other components of blood.
These excitations contaminate the tryptophan decay kinetics and thus complicate the lifetime data analysis.
CSI: The Age of the Bloodstain
Estimation of the age of human bloodstains is of great importance in forensic practices, but it is a challenging task because of the lack of a well-accepted, reliable, and established method.
Herein, we demonstrate a novel method for bloodstain dating based on the fluorescence lifetime of blood. We show that the intrinsic fluorescence lifetime quickly.
Despite various methods and progress in related bloodstain techniques , determining the age of a bloodstain at a crime scene is one of the greatest and oldest challenges in forensic science. Mikhail Berezin and co-workers, Washington University School of Medicine, USA, have developed a novel method to evaluate the age of a bloodstain in a crime scene within the first week. The method is fast ca. Therefore, the time-related degradation of proteins in blood reflects the blood age. This approach minimizes problems with sampling and provides more accurate results.
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Dating bloodstains with fluorescence lifetime measurements
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Bloodstain age analysis: toward solid state fluorescent lifetime measurements. Author(s): Kevin Guo; Date Published: 22 March PDF: 7 pages. Proc.
Lydia Sauer, Christopher B. Komanski, Alexandra S. Vitale, Eric D. Hansen, Paul S. Fluorescence decays were detected in two spectral channels — nm; — nm to determine fluorescence lifetimes of endogenous fluorophores in their specific spectral emission ranges. Blood samples from a healthy subject and a patient with PED were investigated in a quartz cuvette.
Additionally, ex vivo studies of human blood help to better interpret FLIO images.