Polymerase Chain Reaction, or PCR Applications.
PCR Applications Polymerase Chain Reaction, or PCR, is a procedure that was invented in the late 1980's and is widely used in the selective amplification of a chosen region of a DNA molecule. This chosen region can be from any part of the DNA molecule, however PCR will only work if the base sequences of the 3' and 5' ends are known. This is to ensure that two short oligonucleotides, acting as primers, can anneal onto the DNA strands and initiate DNA synthesis reactions. The process of PCR is dependant on the thermostable DNA pol I enzyme from the bacterium Thermus aquaticus The basic procedure of PCR is several cycles of denaturation, hybridisation and synthesis resulting in the eventual synthesis of several hundred million copies of the amplified DNA fragment (see Fig.1 for the overall stages of PCR). Following its completion, a sample of the mixture is analysed by agarose gel electrophoresis, where it is visible as a discrete band by staining with Ethidium Bromide. Fig.1 Summary of PCR PCR is a very sensitive technique and because of this it is used worldwide in molecular biology. There are many applications of PCR, all of which have aided the current knowledge into DNA sequencing and cloning. PCR is frequently used when screening gene libraries after standard cloning experiments. This method can identify and isolate a clone carrying a particular region of the
DNA fingerprinting and its use in crime detection.
DNA fingerprinting and its use in crime detection This essay will discuss the issues surrounding the use of DNA fingerprinting in the prevention of crime. A description of the methods used to create a DNA fingerprint and the retrieval of DNA evidence from crime scenes. The current debates over the validity of DNA fingerprinting and its use as evidence in the courtroom also the ethical problems surrounding the present DNA database. In humans, a DNA molecule consists of two strands that wrap around each other to resemble a ladder whose sides, made of sugar and phosphate molecules are connected by rungs of nitrogen-containing chemicals called bases. Each strand is a linear arrangement of repeating similar units called nucleotides, which are each composed of one sugar, one phosphate, and a nitrogenous base. Four different bases are present in DNA, which are adenine thymine cytosine and guanine. The particular order of the bases arranged along the sugar-phosphate backbone is called the DNA sequence. This sequence specifies the exact genetic instructions required to create an organism with its own unique traits. The two DNA strands are held together by weak bonds between the bases on each strand, forming base pairs. Genome size is usually stated as the total number of base pairs, the human genome contains roughly 3 billion base pairs. Humans have 23 pairs of chromosomes
The Emergence of SNPs in Genetic Medicine.
The Emergence of SNPs in Genetic Medicine Name: Simpson Chan Student # 992452458 TA Name: Rahul Tutorial: L0101 B, Tues 1-4 Forensic DNA and Ancient DNA Since the discovery of techniques that allow for DNA analysis and sequencing, not only did it impact the field of genomics, but it also stimulated other fields of applications. (Capelli et al, 2003). Two unconventional and ways of applying these techniques, ancient DNA (aDNA) analysis and forensic DNA profiling (Capelli et al, 2003), are branches of this discovery that intertwine in respect to their methodologies and approaches. In this commentary, I will attempt to analyze the criteria of authentication, the different aspects of the purpose of DNA analysis, and the problems regarding contamination of the two unconventional applications of DNA analysis. DNA analysis has become an effective procedure in forensic genetics. Prior to 1985, the methods of analyzing biological samples were limited to only conventional blood group and enzyme analysis in criminal cases (Capelli et al, 2003). These methods were informing but nevertheless only gave surface analysis. The advent of the polymerase chain reaction (PCR) changed this phenomena and made DNA analysis an endless scope applicability. Capelli et al states that it allowed forensic experts to address the most inaccessible sources of DNA evidences (such as cigarette butts,
Comparison of Traditional and Modern Approaches to the Identification of Bacteria.
Comparison of Traditional and Modern Approaches to the Identification of Bacteria Wei Na (ID: 329877) Correspondence: Tel: 0121 257 1044 E-mail: [email protected] The practical Report is for BSM 236 Microbes and Man. Department of Biological Science. The University of Birmingham ABSTRACT INTRODUCTION Classification and identification of organisms are two separated but inter-related processes. Classification involves the identification of groups of organism that share common properties and that differ from other groups. The classification and identification of organisms are two separate but inter-related processes. Classification involves the identification of groups of organism that share common properties and that differ from other groups. Identification entails the assignation of an unknown organism to a group within a scheme of classification. Classification Classification is the process of recognizing and describing groups of living organism. Classification is important. It is an activity essential to all scientific work. It would be impossible to make any generalizations about microorganisms and their role in nature if we could only refer to each strain by a different and arbitrary name. We must arrange microorganisms into groupsthat share common properties, so that we can talk about sets of strains that have properties in common. Identification
In heart diseases, time only makes a physical injury worse. If starved for oxygen
Ceren Yalaz 10-6 11.11.2005 Abstract of "Rebuilding the Heart" (1) In heart diseases, time only makes a physical injury worse. If starved for oxygen, heart cells die, their places filled not by fresh replacements but by scarring. Burdened with useless tissue, the heart needs to work harder to pump the blood. The overworked heart gets bigger and it can never catch up with its old pace. Despite doctors' efforts to save them with drugs, catheters, stents and surgery, 5 million Americans currently suffer from heart failure. So cardiologists have started shoring up the dying hearts with stem cells, immature cells that can be coaxed into transforming into many different types. In spite of the encouraging results of the experimental surgeries, noone knows how the treatment works. How the stem cells renew the tissue or the side-effects, are unkown. There are many experiments done on this issue: 1)mice who -deliberately caused to- suffer heart attack, cured by transmission of bone marrow rich in stem cells. 2)In Gremany, the hearts of 60 patients, who suffered heart diseases, were transmitted bone marrows by catheters; their hearts pumped more blood, strongly. 3)In Pittsburgh University, 100 patients' hearts pumped more blood after stem cell treatment, without any side-effects. 4)In Equador Republic, 10 patients with were ejected stem cells obtained from the fetus.
Genetic-Fingerprint or DNA-profiling
Genetic-Fingerprint or DNA-profiling DNA profiling is only possible because we have within the non-coding regions between genes short sequences of bases called core sequences. They repeat themselves over and over again (up to 100 times). These repeated regions of DNA are called minisatellites (or variable number tandem repeats), and each individual has different numbers of repeated core sequences. DNA-profiling is based on two observations: - The number of repeats of a core sequence tends to vary considerably from person to person (the greater the no. of repeats, the longer the minisatellites, therefore each individual has different sized minisatellites). - Each individual has 50-100 different types of minisatellites made from different core sequences. It is almost impossible to find two individuals having matching minisatellites all of the same length (only they would be identical twins), there is only the chance to find very similar minisatellites. Therefore it is important to choose some that show the most variation between people. Making a DNA fingerprint There are 4 main steps for making a DNA fingerprint: Extraction › digestion › separation › hybridisation Extraction A sample of tissue containing cells with a nucleus (e.g. blood, a hair root or semen containing a few sperm cells) is taken to the laboratory where DNA is extracted by shaking the sample in
Who were the Neanderthals? Discuss the importance of genetic evidence for understanding Neanderthal extinction
Who were the Neanderthals? Discuss the importance of genetic evidence for understanding Neanderthal extinction. Neanderthals, a species of Homo Neanderthalensis originated in Europe and parts of western Asia from about 230,000 to 29,000 years ago, during the Palaeolithic period. The relatively large number of Neanderthal fossils and their good preservation offers the possibility of healthy assumptions about their evolution and paleobiology. Nevertheless, debate still continues on important issues, and this suggests that deeper hypothetical and methodological differences lie at the root of the lack of agreement. Such disagreements are not likely to be determined by further fossil findings, but rather require critical re-evaluation of the evidence at hand and the purpose of novel techniques and perspectives. The Neanderthals are best known ancient humans for two of the main reasons. Firstly, they lived in the region which has been explored more than any other for its prehistory- Europe. Secondly, many of them lived in caves, and they adopted the habit of burying their dead in the caves in which they lived. This has meant that Neanderthal bodies have had a greater chance of becoming fossilized, since they were protected by burial from destruction through erosion, trampling or scavenging. Moreover, it is these caves that can also hint at intricacy on how these Neanderthals
Describing how the structure of DNA is suited to its role in Cell Division and Protein Synthesis.
Matt Walker 12GIR Describing how the structure of DNA is suited to its role in Cell Division and Protein Synthesis. DNA is found in every cell nucleus. The nucleus contains genetic codes, these codes decide a species inherited characteristics. Cell division is a process of replacing lost or damaged cells and aiding growth. To produce new cells proteins need to be manufactured this is done by a process called Protein Synthesis. The role of DNA in these two processes is very important. DNA controls the manufacture of proteins and these proteins are what make us unique. Therefore it is important to understand the structure of DNA and how it is suited to its role in these two processes. Structure of DNA A strand of DNA is made up of a double helix. When it is unwound it consists of phosphate, sugar and one of four organic base/nitrogen molecules called nucleotides. The sugar and the phosphate form the two strands along the sides of the helix and the bases are joined by hydrogen bonds that form ties like rungs on a ladder. The role of DNA in Cell Division DNA is found in the cell nucleus, which has a Nuclear Envelope Pore. The role of DNA is to provide instructions for proteins to be produced in the cytoplasm. However, DNA can't pass through the Nuclear Envelope Pore of the nucleus to the cytoplasm. Therefore the DNA has to pass accurate instructions from the nucleus to
Biology - PCR Lab
Isolation, Amplification, and Characterization of a Segment of Human DNA Mar. 12/06 Planning (a): Introduction: Deoxyribonucleic acid (DNA) is a nucleic acid that holds genetic information specifying the biological development of all life forms by establishing the inherited structure of protein in a cell. It consists of two long chains of nucleotides that coil into a double helix shape, which is similar to the form of a winding staircase. It is able to synthesis RNA (ribonucleic acid) and duplicate itself. Each nucleotide of DNA is made up of three different units: a phosphate group, a sugar molecule (deoxyribose), and one of four nitrogenous bases. The bases are either cytosine (C), thymine (T), adenine (A), or guanine (G). In Eukaryotic cells, DNA is found in the nucleus, and is locked in "threads" called chromosomes. There are 23 pairs of chromosomes found in humans, creating a total of 46. In the entire human genome, the amount of DNA is 2.8 x 109 base pairs in length. ** In this lab PCR (Polymerase Chain Reaction) was used for the purpose of amplifying the Alu DNA nucleotide sequence found at the TPA25 (tissue plasminogen activator) locus on chromosome 8. The Alu insertion is also found on the ACE, PV92, APO, FXIIIB, D1, A25, and B65 loci, and is only present in primates. When testing for the insertion the genotypic results are either be homozygous
SDS gel electrophoresis and Western blotting.
SDS gel electrophoresis and Western blotting. Introduction Electrophoresis is the migration of charged molecules in solution in response to an electrical field. (SDS PAGE) Polyacrylamide sodium duodecasulphate gel was used in this investigation in order to determine the molecular weights and possible identification using western blot of particular serum proteins. Using electrophoresis, provided a means of separating proteins of a given molecular weight (markers) and thus through this the molecular weight of the unknown serum proteins. The proteins were held within a porous gel which acts as a sieve by retarding the larger molecules whilst allowing migration freely through the pores of smaller molecules. The (PAGE) gels retain the larger molecules in the gel while the (SDS) denatures the proteins. (SDS) is an anionic detergent which wraps around the polypeptide backbone and binds to the proteins and in so doing conferring a strong negative charge to the amino acid sequence in proportion to its length. (SDS) breaks up the two and three dimensional structure of the protein by adding a negative charge to all the amino acids straightened out. In denaturing, (SDS PAGE) separations, migration is determined not by intrinsic electrical charge of the polypeptide but by molecular weight between log molecular weight and (RF) distance migrated by the protein/ distance migrated by
