SIB2003 Molecular Biology Practicals
Manipulation and analysis of DNA using standard Molecular Biology Techniques.
During the course of the next three practical classes you shall be performing a number of techniques in order to isolate and manipulate DNA from bacteria. The practicals are spread over three sessions, the techniques that you will perform are indicated below:
Practical 1 Isolation of plasmid DNA from three cultures of E.coli using a method known as the alkaline lysis method.
Practical 2
(Part A) Digestion of the plasmid DNA that you have isolated, with restriction enzymes.
Practical 2
(Part B) Transformation of bacterial cells (E. coli) with:
a) No DNA
b) Plasmid DNA
c) digested DNA
Practical 3 Analysis of DNA from practicals 1 and 2 using the technique of agarose gel electrophoresis and analysis of transfomed E. coli from practical 2 (part B)
Whilst the practical classes deal with different techniques, it is important that you write it up as a single laboratory report. The write-up should contain a general introduction written as an overview. The methods and results should be written up as separate sections within the single write-up and the conclusion should be a general summing up exercise where you can discuss the relative success of each practical. Please remember that the write-up should be written up in the passive and in past tense. Further guidelines for the write-up are provided separately and uploaded on Unilearn.
Practical 1
In this experiment we were meant to observe the transferring of DNA. There are many ways in which DNA can be transferred into an organism, for example; transformation, transduction, and conjugation. In our experiment we used
In preparing for the bacterial transformation, DNA plasmid is introduced into the E. coli cells that will express newly acquired genes. Two tubes were used and labeled both as +pGLO and -pGLO. A solution of (CaCl2) was transferred 250 µl onto the two tubes. The tubes were placed on the ice. A sterile loop was then used to gather a single colony of bacteria from a starter plate. Now, that both tubes contain bacteria they were placed on the ice for 10 minutes. Four agar plates were labeled as: +pGLO LB/amp, +pGLO LB/amp/ara, +pGLO LB, -PGLO LB/amp. Heat shock was used to transfer both the +pGLO and -pGLO, at exactly 42°C. Time was observed for 50 seconds and quickly return the tubes to the ice for another 2 minutes. As the tubes, cold down they
Each human being has something called DNA. DNA is described as genetics and an extremely long macromolecule that is the main component of chromosomes and is the material that transfers genetic characteristics in all life forms. DNA constructs of two nucleotide strands coiled around each other in a ladder like arrangement with the sidepieces composed of alternating phosphate and deoxyribose units and the rungs composed of the purine and pyrimidine bases adenine, guanine, cytosine, and thymine. Each chromosome consist of one continuous thread-like molecule of DNA coiled tightly around proteins and contains a portion of the 6,400,000,000 basepairs that make up your DNA.
In this investigation pUC19 plasmids were used as the vector due to its small size of 2686bp, high uptake efficiency by the host and fast replication time. Important features of this plasmid include the origin of replication and multiple cloning sites (MCS). The origin of replication allows the plasmid to replicate inside the host bacterium. The MCS is located within the lacZ gene and contains unique sites for the Xbal & EcoRI restirction enzymes to cut and produce sticky ends for the CIH-1 gene to bind to. Furthermore, the pUC19 plasmid also contains an ampiccilin resistance gene so only transforemed E.coli are able to remain viable when spread on the agar plates that also has the addition of ampiccilin. The lacZ gene encodes the β-galactosidase enzyme which aids in indentifying the recombinant E.coli from the non recombinant cells (Coventry University 2016).
Genetic Transformation of E. coli Using pGLO Plasmid Introduction The bacteria E. coli is a competent bacteria which has the ability to accept foreign pieces of DNA and express them in itself. In this lab will be testing the hypothesis that E. coli is competent and can express foreign DNA by depositing pGLO DNA, which was created from the same DNA that makes jellyfish fluorescent, into the E. coli to make the bacterium glow. We are also testing the hypothesis that the pGLO DNA can make the E. coli resistant to ampicillin.
The goal of this experiment was to investigate genetic transformation of E.coli through the reaction of organism to the vector pGLO plasmid. As mentioned, the pGLO plasmid contains genes coding for resistance to ampicillin (amp), and genes coding for production of the green fluorescent protein (GFP) which glows under UV light in the presence of arabinose (ara),which serves as a reporter gene. This green fluorescent
coli are picked and the plasmids are purified. The purified plasmids are used as a template for the sequencing reaction. The objective of the lab was to learn how to use the polymerase chain reaction (PCR) to amplify the small subunit ribosomal RNA gene from a bacteria colony, also be able to run an agarose gel to visualize the resulting PCR amplifications and extract the amplified DNA from the agarose gel.
Next the tubes were placed in an ice bath, while obtaining a sterile loop to swipe a single colony of E.coli to put into the tube. After gently swiping a colony onto the loop, it was then spun in the +pGLO tube to get it to come off, returned to the ice bath. Next using a different sterile loop, it was swooped it in a container labeled pGLO plasmid DNA and again spun it ONLY into the tube with the solution labeled +pGLO to get it to come off. After about 10 minutes on ice the tubes were then placed into a 42ºC water bath for 50 seconds exactly, and immediately after placed them back into the ice bath. Finally, after 2 more minutes in the ice bath the tubes were separated into 4 containers. 250 ul of +pGLO solution was added to the containers containing +pGLO, LB broth, with ampicillin and +pGLO, LB broth, ampicillin, with arabinose. Also 250 ul of the –pGLO solution was added to the 2 containers containing LB broth, and ampicillin, with LB broth. Using a sterile loop for each plate the solutions were spread out gently and thoroughly on to the containers with agar. After the containers were incubated in 37ºC for at least 24 hours, the results were observed and disposed of (Weedman,
The results of our lab did not go as planned for the co-transformation. Specifically, the plates that used both plasmids were killed off by the anti-biotics, proving that both plasmids were not able to be transferred into the e. coli.
After the incubation, 1.5 mL of each of the three cultures were added to eppendorf tubes and centrifuged at 13,200 rpm for 1 minute. An alkaline lysis procedure like that of Birnboim and Doly was then performed to extract the plasmid DNA with 200 μl of alkaline SDS detergent solution (Birnboim & Doly, 1979). After
The purpose of the experiment was to isolate plasmid DNA, followed by restriction digestion using restriction endonucleases and then visualizing the digested fragments after subjecting to gel electrophoresis. Plasmid DNA (pSP72 DNA) was isolated from Escherichia coli KAM32 (E.coli) cultures using the QIA prep miniprep kit and then subjected to restriction digestion by EcoRI and HindIII. The restriction digested DNA was then loaded into the wells of 0.7% agarose gel and subjected to electrophoresis. It can be concluded from our results that our plasmid DNA isolation was successful and the restriction digestion results were partially in agreement with our hypothesis.
Transformation is the directed modification of a genome by the external application of DNA from a cell of different genotype (Griffiths and Miller).Bacterial transformation is the easiest type of transformation to create and study due to the single cellularity of bacteria and its
DNA forensics is a division of forensic science that focuses on the use of genetic material in criminal investigation to answer questions pertaining to legal situations, including criminal and civil cases. Through DNA testing, law enforcement officers are able to identify human remains or the individual responsible for a crime. DNA testing is a highly advanced scientific process that involves replicating the human DNA sequence to create a genetic map of an individual. Because of its reliability, DNA testing has become a significant factor in criminal cases. However, it has also been identified as having the potential to violate privacy and constitutional rights. The DNA identification process consists of five stages. These five stages
Plasmid DNA with Restriction Digest: The purpose of restriction digest of plasmid DNA is to understand how each DNA plasmids was cut with the given restriction enzymes and perform gel electrophoresis to observe the samples. Nine restriction digests were created, containing three digests for each of the three plasmid DNAs identifying as recombinant, non-recombinant, and unknown. Out of the nine digests, six are actual digests and three are undigested controls. A master mix is created to add to each of the nine samples with its following stock ingredients: 10 ul of 2X Reaction Buffer, 1 ul of Nco1, X ul of sterile water (Single digest), 10 ul of 2X Reaction Buffer, 10 ul plasmid DNA, 1 ul Nco1, 1 ul of Not1, and X ul of sterile water (Double
DNA is a term that has been used in science as well as in many parts of daily