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The Action of Salivary Amylase practial report
The Action of Salivary Amylase practial report
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I. Introduction
The problem While DNA profiles can be obtained from evidentiary swabs, forensic science is currently deficient in the methods to determine the tissue source of the DNA. While proper confirmatory tests exist for biological fluids such as semen1,2 and blood3, similar tests for the confirmatory identification of saliva are lacking. Being able to confidently identify the source material of the DNA may help criminal investigators corroborate the claims of an alleged victim or suspect. For example, analysis of an evidentiary swab from an alleged suspects finger. The alleged victim states that she was sexual assaulted and the suspect used his finger to penetrate her. The alleged suspect states that no sexual assault occurred and
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This method is flawed for various reasons. The first is that tests rely on α-amylase activity (such Phadebas®), which can be a problem on degraded or weathered samples as well as samples that are contaminated with factors that may inhibit activity. Another problem is that immunoassays (such as RSID™-Saliva) are inherently presumptive because one can never be certain that an antibody is not cross-reacting with a non-target molecule. An additional problem lies within the fact that various other body fluids contain α-amylase, although typically in levels much lower than those seen in saliva. For example, typically saliva will contain 263000 to 376000 IU/L of α-amylase, where urine will contain 263 to 940 IU/L, blood will contain 110 IU/L, and semen will contain 35 IU/L.4 However, false positives have been …show more content…
I will also be collecting 10 samples of other bodily fluids (peripheral blood, semen, vaginal secretions, menstrual blood, and urine) from different individuals using Diva Cups®, SoftCups™, sterile collection cups, while obtaining peripheral blood samples from a certified phlebotomist. I will be enriching whole saliva for small peptides using a combination of a TFA acid crash and 30 kDa molecular weight cut-off filters. I will then digest the peptides for analysis. I will be testing this prep method using LCMS. Once a sufficient prep method is devised, I will analyze 50 saliva samples using ultra-performance liquid chromatography–quadrupole–time-of-flight mass spectrometry (UPLC QTOF) in order to make a structural confirmation of the protein sequence via tandem MS/MS. I will be using reversed phase chromatography with a gradient of acetonitrile (ACN) and water as my solvents. I will be repeating the method on 10 samples of other bodily to ensure that the biomarkers chosen as markers for confirmatory identification of saliva are not present in any other
U.S. Department of Energy, Office of Science. (2009). DNA Forensics. Retrieved from Human Genome Project Information: http://www.ornl.gov/sci/techresources/Human_Genome/elsi/forensics.shtml
In certain situations, it is necessary to identify DNA retreived from a sample. When there is a
The analysis of the samples should be used only to confirm or negate match between the sample taken from the crime scene fgand the sample taken from the suspect. That is, it should sdfremain as an identifgication tool only. There should be no further analysis of the DNA to suggest psychological characteristics that would make the suspect more likely to have cdfommitted the crime. This rule should apply also to samples taken from convicted dfdoffenders for a data vor dagta bank.
. DNA can be left or collected from the hair, saliva, blood, mucus, semen, urine, fecal matter, and even the bones. DNA analysis has been the most recent technique employed by the forensic science community to identify a suspect or victim since the use of fingerprinting. Moreover, since the introduction of this new technique, there has been a large number of individuals released or convicted of crimes based on DNA left at the crime scene. DNA is the abbreviation for deoxyribonucleic acid.
Nowadays, DNA is a crucial component of a crime scene investigation, used to both to identify perpetrators from crime scenes and to determine a suspect’s guilt or innocence (Butler, 2005). The method of constructing a distinctive “fingerprint” from an individual’s DNA was first described by Alec Jeffreys in 1985. He discovered regions of repetitions of nucleotides inherent in DNA strands that differed from person to person (now known as variable number of tandem repeats, or VNTRs), and developed a technique to adjust the length variation into a definitive identity marker (Butler, 2005). Since then, DNA fingerprinting has been refined to be an indispensible source of evidence, expanded into multiple methods befitting different types of DNA samples. One of the more controversial practices of DNA forensics is familial DNA searching, which takes partial, rather than exact, matches between crime scene DNA and DNA stored in a public database as possible leads for further examination and information about the suspect. Using familial DNA searching for investigative purposes is a reliable and advantageous method to convict criminals.
Another discrepancy between actual forensics and how it is portrayed in the media is the availability of information in databases. There is only a small percentage of the entire population’s fingerprints or DNA samples stored within databases such as the Integrated Automated Fingerprint Identification System (IAFIS). This makes finding a match between a DNA sample or fingerprint difficult, as a match would only be found if the person’s information was already stored within the database. If there is no match previously stored in a database, the fingerprint or DNA sample could be potentially rendered useless within a trial. Typically, in order to perform an analysis, investigators must already have a suspect in mind and request a DNA or fingerprint sample from him or her. If the suspect does not want to provide one however, the sample collected as evidence may not count as valid. The CSI effect creates an idealized image that all crimes can be solved with a hair or drop of blood, but this is not always the case in real life.
Technology has improved innumerable sectors in industries such as sports. Stadiums, scoreboards, sound systems, training facilities, athletic wear, and protective equipment have been upgraded over the last few decades. Specifically, technology has improved protective equipment to keep athletes safe. Currently, some of the most worrisome injuries are concussions and other head injuries; they occur in all different types of sports and activities, but the highest amount of head injuries occur in football (Stone). For this reason, protective headgear is of the highest importance for professional and nonprofessional football players. New discoveries about brain injuries have made a priority to protect the head.
The most important type of evidence is DNA. When DNA testing takes place, the samples are collected from the suspect and the crime scene. These evidences include hair, fingerprint, human secretions, blood, semen and other bodily fluids, are collected and sent to the lab for further investigation.
The criminal justice system has changed a lot since the good old days of the Wild West when pretty much anything was legal. Criminals were dealt with in any fashion the law enforcement saw fit. The science of catching criminals has evolved since these days. We are better at catching criminals than ever and we owe this advancement to forensic science. The development of forensic science has given us the important techniques of fingerprinting and DNA analysis. We can use these techniques to catch criminals, prove people's innocence, and keep track of inmates after they have been paroled. There are many different ways of solving crimes using forensic evidence. One of these ways is using blood spatter analysis; this is where the distribution and pattern of bloodstains is studied to find the nature of the event that caused the blood spatter. Many things go into the determination of the cause including: the effects of various types of physical forces on blood, the interaction between blood and the surfaces on which it falls, the location of the person shedding the blood, the location and actions of the assailant, and the movement of them both during the incident. Another common type of forensic evidence is trace evidence. This is commonly recovered from any number of items at a crime scene. These items can include carpet fibers, clothing fibers, or hair found in or around the crime scene. Hairs recovered from crime scenes can be used as an important source of DNA. Examination of material recovered from a victim's or suspect's clothing can allow association to be made between the victim and other people, places, or things involved in the investigation. DNA analysis is the most important part of forensic science. DNA evidence can come in many forms at the crime scene. Some of these forms include hair; bodily fluids recovered at the crime scene or on the victim's body, skin under the victim's fingernails, blood, and many others. This DNA can be the basis of someone's guilt or innocence; it has decided many cases in the twentieth century. As the times continue to change and the criminals get smarter we will always need to find new ways to catch them. Forensic science is the most advanced method yet, but is only the beginning. As the field of science grows so will the abilities of the
Once a crime has been committed the most important item to recover is any type of evidence left at the scene. If the suspect left any Deoxyribonucleic acid (DNA) at the crime scene, he could then be linked to the crime and eventually charged. A suspect’s DNA can be recovered if the suspect leaves a sample of his or her DNA at the crime scene. However, this method was not always used to track down a suspect. Not too long ago, detectives used to use bite marks, blood stain detection, blood grouping as the primary tool to identify a suspect. DNA can be left or collected from the hair, saliva, blood, mucus, semen, urine, fecal matter, and even the bones. DNA analysis has been the most recent technique employed by the forensic science community to identify a suspect or victim since the use of fingerprinting. Moreover, since the introduction of this new technique it has been a la...
"Using DNA to Solve Crimes." U.S. Department of Justice: National Institute of Justice. (September 9, 2014). Web. 29 May 2015.
Strands of human hair situated at the crime scene gives exceptionally solid sign that an individual was at that area, yet it can likewise be useless if the fibres were found outside and, subsequently subject to the elements such as wind, and if the full length of the strand is not present (Dasgupta, 2007). Hair without anyone else 's input is essential, but rather the most imperative DNA evidence connected with hair fibres originates from the cellular material at the root of the hair strand. In a way, the microscopic particles of follicle give the most solid proof. The protein called keratin is the key substance that goes with the follicle, and that gives the best distinguishing proof. On the off chance that the hair is taken off by the root, for example that could happen when an individual is guarding him or herself against an attacker, then the hair fibres are essential (Innes, 2000). Hair that does exclude follicular material is a great deal less dependable. Hair fibres that do exclude keratin are helpful in distinguishing a category of individual into which a suspect may fit, however they are not complete evidence that the hair originated from the suspect (Innes, 2000). Therefore, personally, hair fibres are less important than fingerprints and DNA evidence acquired from saliva or blood. Fingerprints are not DNA evidence, but still they are extremely dependable types of evidence. DNA obtained from bodily fluids, in any case, is the most profitable type of evidence
Dental hygiene is a dynamic and challenging career that offers team work, personal growth, and extraordinary benefits, and it is the perfect career for me. As a health care professional, the dental hygienist is an important member of the dental team providing patient care. Good qualities for a dental hygienist are compassion and enjoying talking to people which are two qualities that fit my personality. I love the thought of knowing I made a positive impact in a person's health. Becoming a dental hygienist professionally requires you to obtain an associate degree in dental hygiene. They affect the average American by educating them about dental care. A dentist helps people with their dental health, which can greatly impact a person’s day-to-day life.
Bite mark analysis method have evolved over the years to give more reliable and reproducible results. The examination and analysis of bite marks is used in an attempt to scientifically link the dentition of a potential biter with the bite mark. MacDonald defined bite mark as ‘a mark made by teeth, either alone or in combination with other mouth parts’. Bite mark evidence has been used with increasing frequency over the years, possibly due to raised awareness and recognized of such injuries, along with an increase in the number of violence involving bite mark injuries.
Forensic odontology is a discipline within forensic science that involves the management, examination, evaluation and presentation of dental evidence in criminal or civil proceedings (1). The main goal of forensic dentists/odontologists is to identify humans (1, 3). Forensic dentists have many methods that are used for dental identification. Some of these methods include bite mark analysis, labeling of dental prosthesis (dentures), rugoscopy (palatal rugae which are located on the roof of the mouth), and cheiloscopy (lip prints) (1). This paper will focus on the process that forensic dentists take to identify humans using teeth, how forensic dentists conduct bite mark comparisons, the methods/techniques that are used to do these comparisons and why forensic odontology is an important discipline in forensic science. The references cited throughout this paper were chosen as they were informative and clear. The majority of the articles cited contained multiple photos that made the information a lot easier to follow.