Restriction enzymes are able to cut polypeptide chains at specific sites. Restriction digest is the process of using several different restriction enzymes to cut DNA into small pieces that can be sequenced. You are then able to line up the overlap in the different sequences to determine the complete sequence of the DNA. Restriction enzyme sites are used to make maps of DNA. Restriction enzymes provide a critical tool for molecular biologist to predictable fragment a given DNA molecule, which allows them to analyze the structure and features in fine detail.
In the 1960s Stuart Linn and Werner Arber found both modification enzyme and restriction nucleases in extracts of E. coli strain B. This explained why sometimes when E. coli was transfected …show more content…
An important part of this is which enzymes will work in the same buffer. Using multiple restriction enzymes is necessary because without multiple enzymes it would impossible to determine the specific sequence of the DNA strand. Once you have determine which restriction enzymes you want to use, you will then set up the digest. You will need several 1.5 mL tubes (at least 7 tubes if you are using 3 enzymes). In each tube you need to add some of your DNA sample. You will then add different combination of restriction enzymes to each tube. The typical order of combination of enzymes would be 3 tubes that have one enzyme each, 3 tubes that have 2 enzymes each and one tube that has all the enzymes. It is necessary to have different combinations of the restriction enzymes so that you get a better idea of how the enzymes cut in relation to each other. Then you will add buffer, BSA, and water. Once the tubes are mixed they have to be incubated so that the restriction enzymes have time to cut the DNA into fragments. After the incubation the tubes of DNA fragments are ran through a gel electrophoresis, which allows you to visualize the results of the
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We use eight lanes putting the enzymes, and the DNA of the suspects to the lane. It is important to do this slowly and with care so as to ensure we put each solution in the correct tubes. You also have to plug it to the power source. Red is the negative while black is the positive and it should be at 150V for about forty minutes. Evaluation of the DNA bands
The vital components and techniques of gene cloning are as follows, the DNA sequence that contains the desired gene (EZH2) is amplified by Polymerase chain reaction. PCR was established by Kary Mullis in 1985, popularly known to amplify target sequences of DNA (EZH2) to a billion fold in several hours using thermophilic polymerases (Taq) ,primers and other cofactors (Sambrook and Russell, 2001). Three crucial steps are involved which are Denaturation (at 95°), Annealing of the forward and reverse primers (55-65°) and lastly primer extension (at 72°). After amplification the desired sequence is integrated into the circular vector (pbluescript) forming the recombinant molecule. For the compatibility of the insert and vector, both were digested with (EcoR1) so the same cohesive ends are generated in both, making it easier to ligate. EcoR1 is a restriction enzyme that belongs to the type II endonuclease class which cuts within dsDNA at its recognition site “GAATTC” (Clark 2010; Sambrook and Russell, 2001).
The goal of the restriction digests is to be able to cut the plasmids at specific sites. This step
We placed the gel into the running chamber, and then we completely covered the gel with TAE. 3 microliters of loading dye was added to each tube; this would help distinguish the enzyme from the gel. As before, we tapped the tube on the table to mix. Then we carefully added each of the four samples into their own wells. A total of 33 microliters of each sample was poured into each well. Afterwards, we attached the positive and negative electrodes to their corresponding terminals on the power supply and gel box. We turned on the power to around 80 volts and waited 45-60 minutes for the loading dye to move down the gel approximately 6-8 cm. Finally, we were able to visualize the DNA in the gel and write down the
Restriction Enzyme Digestion – The experiment was begun after putting on gloves to avoid any chemical contact with the skin. Four microtest tubes were obtained, and each of them was labeled to contain the different enzymes or suspect DNA. Two of the microtest tubes were used for suspect one and the two different restriction enzymes, while two other microtest tubes were labeled for suspect two and the two restriction enzymes. After labeling the tubes, the contents that were at the bottom were taken out by slightly tapping them. Then to begin setting up the enzyme reactions, a micropipette was used to obtain 10 μL of the reaction buffer which was added to each of the four test tubes. The buffer is important because it carries the electrical current from the power supply in the gel. After the reaction buffer was in each, the microtest tubes were individually filled with their specific enzymes and DNA, shown in summary through Table 1.1 below. The restriction enzymes are used to cleave the DNA at specific
The pGLO plasmid will transform the E. coli bacteria with a gene called GFP that codes for the Green Fluorescent Protein in the genetic code. GFP was discovered in the jellyfish, Aequorea victoria as a green fluorescent light emitted from the jellyfish. It was typically seen in the dark upon its activation and since then has been used in studies relating to genetic transformation. (Chalfie and Tu 1994) The majority of the studies test the many different factors that are required in the transformation of pGLO which will determine the functionality of GFP in the E.coli bacterium. The first experiment in transforming GFP and E. coli was completed in 1994 by Chalfie and was further refined the same year. The experiment proved the importance of using restriction enzymes, and DNA ligase in the process of transforming GFP to identify arabinose as the primary activator, and to identify the ampicillin
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.
Restriction enzymes cut DNA at certain sites to create multiple DNA fragments. Restriction enzyme HindIII has known DNA fragment lengths and recognition sites when digesting lambda DNA, while the lambda DNA recognition site for restriction enzyme XhoI is unknown. The goal of this study is to determine the lambda recognition site of XhoI by comparing a HindIII digest and a HindIII and XhoI double digest on an electrophoresis gel. The HindIII digest had a band at 9.4 kb, but this band was not visible in the double digest, therefore we concluded the recognition site for XhoI was around 9.4kb. There were also two additional DNA
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)
Enzymes are applied to DNA to break it into smaller pieces which are called restriction endonucleases. These restriction endonucleases become
Bacterial transformation is the process of moving genes from a living thing to another with the help of a plasmid.The plasmid is able to help replicate the chromosomes by themselves; laboratories use these to aid in gene multiplication. Bacterial transformation is relevant in everyday lives due to the fact that almost all plasmids carry a bacterial origin of replication and an antibiotic resistance gene(“Addgene: Protocol - How to Do a Bacterial
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