General Biology I
Lab Report 3
Lab #18: Gel Electrophoresis
Due date: 11/21/13
Name: Jaimin Maknojia
Purpose: The purpose of this lab is to analyze the results of the current criminal investigation.
Introduction: Gel electrophoresis is used to separate molecules like RNA, DNA and proteins. DNA fragments are separated by size and proteins are separated according to the size and their charge. Gel electrophoresis use positive and negative electrode to separate charge particles. The charged particles are attracted to opposite charges (Purdue University 2012). As the DNA has a negative charge the electrical circuit which has positive charge is placed at the bottom of the gel. This causes the smaller DNA particles to move quickly through the gel (Brooker 2012).
In this experiment there are 3 DNA samples provided. The DNA from the blood left on the scene (crime scene DNA). And the DNA’s from the cheek swabs collected from both of the suspect (suspect A and suspect B). These DNA has been given to test for two different markers (Marker 1 and Marker 2) and to found out which DNA has the identical profile. The gel is made of seaweed. It is a gel which consists of small wells at the end of the gel (Biotechnology Learning Hub). The STR stands for short Tandem repeats. The DNA samples are created by 2 versions of genome. One is inherited from the mother and the other is inherited from the father. These genomes are then used to compare the DNA samples.
Materials:
Pre-made agarose gel
Gel box
Pipette man
Pipette tips
DNA solutions: crime scene markers 1 and 2
Suspect A markers 1 and 2
Suspect B markers 1 and
TBE buffer
Carbon fiber electrodes
Power supply
Methods: To begin, an alr...
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...e marker matching, the next step in a forensic investigation would be to test for the remaining 11 markers for a complete DNA profile.
The DNA fingerprinting can be used to find out who are the child’s parents, if got into a situation of a baby getting exchanged. It can also be used to find out who the real father or mother is, if one of them had a relationship with someone else other than their spouse. DNA fingerprinting also allows any adopted child to find out who their biological parents are (Rafael 2009).
References:
Brooker, Robert J., Eric Widmaier, Linda Graham, and Peter Stiling. (2011). Genetic Technology. Biology, 415.
Purdue University Van Project. (1996). Retrieved December 1, 2012. from http://www.chem.purdue.edu/te Rafael. The Benefits of DNA fingerprinting. Retrieved August 22, 2009. http://www.brighthub.com/science/genetics/articles/46432.aspx.
The procedure of the lab on day one was to get a ring stand and clamp, then put the substance in the test tube. Then put the test tube in the clamp and then get a Bunsen burner. After that put the Bunsen burner underneath the test tube to heat it. The procedure of the lab for day two was almost exactly the same, except the substances that were used were different. The
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.
The repeat segments are cut out of the DNA strand by a restrictive enzyme that acts like scissors and the resulting fragments are sorted out by electrophoresis (Saferstein 391). However, there are some drawbacks using the RFLP method in the forensic science community. The RFLP technique requires a large amount of DNA and must be of high quality and cannot be degraded (Jones). Forensic scientists and the law enforcement community determined a need for a DNA profiling method that could be used on smaller DNA samples. Thus, the RFLP technique has been almost entirely replaced by Polymerase chain reaction.
During this time, it could only be used in a lab with semi-intense supervision. Now, fast forward a few decades and there are D.I.Y. at home kits. The process of Electrophoresis starts with an electric current being run through a gel containing the molecules of interest. The molecules will then travel through the gel in different directions and speeds, based on their size and charge, allowing them to be separated from each other. Dyes, fluorescent tags, and radioactive labels can all enable the molecules on the gel to be seen after they have been separated. Because of these identification markers, they appear as a band across the top of the gel. Electrophoresis can be used for many different things. It is used to identify and study DNA or DNA fragments, and helps us to better understand the molecular components of both living and deceased organisms. Electrophoresis can also be used to test for genes related to specific diseases and life altering diagnoses such as Multiple Sclerosis, Down’s Syndrome, kidney disease, and some types of cancer. Electrophoresis also plays a major role in the testing of antibiotics. It can be used to determine the purity and concentration of one specific type of antibiotic or several general antibiotics at a time. Electrophoresis is also extremely useful in the creation and testing of
Keiper L. More states use familial DNA as powerful forensic search tool. Reuters [Internet]. 2011 [cited May 16 2012]; N. page. Available from: http://www.reuters.com/article/2011/03/30/us-crime-dna-familial-idUSTRE72T2QS20110330.
The two modes of analysis that will be used to identify an unknown insert piece of DNA would be plating the transformation cells onto LA plates that have either ampicillin or chloramphenicol and PCR. We will use the PCR thermocycler to denature the restriction enzymes that were specifically used to assimilate the vector DNA. It is important to use the PCR thermocycler because denaturation of the restriction enzyme will prevent the restriction enzyme from cutting the vector DNA, after the insert DNA has assimilated to the vector DNA. After the addition of specific primers that complement the base pair to its corresponding target strand, PCR will be used. Subsequently, Taq polymerase will be used to determine whether the insert DNA has been properly assimilated to the vector DNA. Within this specific situation, the target strand will be the insert DNA. After we let the PCR thermocycler run for approximately 2 ½ hours, we will then put our PCR products in the gel and run the gel to completion. After the gel has run to completion, we will then take a photograph of the gel using the UV transilluminator with the assistance of our TA. If the insert DNA was properly assimilated to the vector DNA, then our corresponding gel photo would have one band. After the cells have been transformed, we would g...
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...
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
There are thirteen standard tandem repeats used in modern forensics, and together these sequences create a DNA profile. Except in the case of identical twins, the probability that two people have the same genetic code at all thirteen core loci is less than one in one trillion (Jones, 2004). Investigators compare these...
Peschel, O., Kunz, S. N., Rothschild, M. A., & Mützel, E. (2011). Blood stain pattern analysis. Forensic science, medicine, and pathology, 7(3), 257-270. http://link.springer.com/article/10.1007/s12024-010-9198-1
"Polymerase Chain Reaction (PCR) Fact Sheet." National Human Genome Research Institute. 10 Dec. 2007. National Institutes of Health. .
LAB REPORT 1st Experiment done in class Introduction: Agarose gel electrophoresis separates molecules by their size, shape, and charge. Biomolecules such as DNA, RNA and proteins, are some examples. Buffered samples such as glycerol and glucose are loaded into a gel. An electrical current is placed across the gel.
Gel electrophoresis is used in a variety of settings, particularly in molecular biology. Besides being used to separate nucleic acids, such as DNA and RNA, gel electrophoresis is also employed to divide proteins (Gel Electrophoresis). According to research, electrophoresis is applied for the following reasons, "To get a DNA fingerprint for forensic pur...
One significant advantage of capillary electrophoresis (CE) is the separation of a broad range of analytes at the same moment. Affinity Capillary Electrophoresis (ACE) is a technique used in order to separate substances which participate either in specific or in non-specific affinity interactions during the electrophoresis process, by using a capillary electrophoresis format. The molecules can be free in solution or they can be immobilized to a solid support (Heegaard, Nilsson and Guzman, 1998).