1. The extremely halophilic archaeon Haloferax volcanii has two very different dihydrofolate reductases by Ron Ortenberg, Orit Rozenblatt-Rosen and Moshe Mevarech.
2. When working with Haloferax volcanii the scientists were trying to figure out what genes control the dihydrofolate reductases and removed the hdrA gene from the H.volcanii and challenged the cells with trimethylprim. When a trimethoprim resistant mutant occurred it was analyzed and there was DNA sequence similar to the amino acid sequence of dihydrofolate reductase. When the scientists used the amplification unit as a probe the chromosomal locus containing hdrB gene was detected. Wanting to determine which hdr gene would have a greater effect on the organism ability to have
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In order to achieve this goal they created variants of each gene. These genes were all removed by a similar process by which the pieces of the gene were cut with different restriction enzymes and purified and cloned in order to give us different plasmids. They were amplified using PCR and these were then integrated into the regions and then grown on media and observed. When there was excision of the gene they were looking to remove these strains were cultivated and given designations. Strain WR 441(hDHFR-2) has the hdrA was deleted, WR445 has a deletion of both genes and WR446 (hDHFR-1) has a deletion of hdrB, WR 447 had hts deleted from it. These strains in turn were grown on three different Medias HY which was the rich media, M which was the minimal media and agar plates. In these experiments they found that WR441 needs nothing else and grew on each media with no other enrichment. However WR446 and WR 445 could grow on minimal medium containing both trimethoprim and thymidine, but only when that medium was supplemented with glycine, methionine, pantothenic acid and hypoxanthine. Another strain WR447 was grown and found that it was auxotrophic for thymidine. However when plasmid pHE4 was added to it could grow on minimal medium containing trimethoprim and thymidine. When the hts was removed the hdrB gene did not have a strong promotor which appeared when the hDHFR-2 didn’t express itself enough to give the organism the trimethoprim resistance it need to get a high copy number. Because of this we can use the hdr gene as an expression point for Hf.volcanii. At the lowest level of expression, only complementation of purine, glycine, pantothenate and methionine autotrophy will occur When the gene has a higher level of expression we can see that there will be prototrophic growth in minimal medium, and when the gene is working at its highest level it will give a resistance to
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 instructor split the class into two separate groups one with the plasmid lux and the other with the plasmid pUC18. Group two was assigned to test the lux plasmid. The, Eppendorf, tubes were labeled “C” for the control plasmid DNA and “lux” for the plasmid lux DNA. The two tubes were then placed into the ice bath. Using a sterile micropipette 5 uL of the lux plasmid was added to the tubes labeled “lux” or 5 uL of the control plasmid was added to the tubes labeled “C” for the control plasmid DNA. Eppendorf tubes had 70 uL of the competent cells added to them with a different transfer pipet. All the tubes were then stored in the ice bath for about fifteen minutes. Another test tube was labeled “NP”, which stands for “No Plasmid”, and 35 uL of competent cells was added to each of the test tubes labeled “NP” during the fifteen minutes. Once the fifteen minutes are up, all three tubes were placed into a preheated water bath at 37 °C for about five minutes. To both the lux
The goal of the restriction digests is to be able to cut the plasmids at specific sites. This step
At the same time, bacterial colonies are needed to be placed into PCR, and use photograph of gel to determine the size of tetracycline resistance genes to distinguish the bacteria. It is relevant to research 1 because serial dilution is the first step to get colonies' samples that is further being used to distinguish plasmids. It is also relevant to research 2 because serial dilution is also the first step to count the frequency of tetracycline resistant. Week 2: Experiment Part B By placing the bacteria into the PCR machine, much more copies of genes would be made to make them visible under electrophoresis, which can then be compared with control ladder to distinguish the kind of bacteria.
Plasmid map of pRSETB. Primers were designed to amplify via PCR to cDNA. The PCR product was digested with XhoI and EcoRI enzymes and ligated into the pRSETB plasmid. The pRSETB plasmid contains a T7 promoter region, is ampicillin resistant, inducible with Isopropyl β-D-1-thiogalactopyranoside IPTG, a molecular mimic of a lactose metabolite that triggers transcription of the lac operon, and has XhoI and EcoRI cut sites. The pRSETB plasmid is transformed into dH5α E. coli and plated on carbenicillin plates. Colonies are selected and grown on a carbenicillin plate while PCR is used to check that the plasmid that was up-taken was not
There were several steps used to acquire the colony necessary for the PCR. First a student forearm was swabbed using a cotton swab, the cells were then placed in an agar plate. DNA was then extracted from the cultured bacteria by using a technique to lyse the cells and solubilize the DNA, then enzymes were used to remove contaminating proteins. The DNA extraction consisted of a lysis buffer that contained high concentrations of salt for denaturing. Binding with the use of ethanol and a washing step to purify the DNA. The final step for the DNA extraction was elution where the pure DNA was release. Proceeding the extraction of DNA the results of the 16s gene amplification were examined through gel electrophoresis it was analyzed by estimating the size of the PCR bands with marker bands. After measuring the success of the extraction, a technique called TA cloning was started. Cloning of PCR products was done by using partially purified amplified products with
Four microcentrifuge tubes were placed in a rack, labeled and numbered, in order to identify the group and the DNA/restriction enzyme that it held. Each of the tubes initially received 10 microliters of reaction buffer. There were two samples of suspect DNA provided along with two restriction enzymes (EcoRI and HindIII). Tubes labeled 1 and 2 received 15 μL of DNA from suspect one while tubes 3 and 4 received 15 μL of DNA from suspect two. Following that, 15 μL of Enzyme 1 (EcoRI) were added to tubes 1 and 3, and 15 μL of Enzyme 2 (HindIII) were added to tubes 2 and 4. (Table 1). The tubes were then gently tapped on the counter to mix the DNA and enzyme solution followed by incubation at 37°C for 45 minutes. After incubation, 5 μL of 10x gel loading dye were added to each of the four tubes of suspect DNA. The tubes were then placed on ice while the gel was under preparation.
Before plating the strains on agar plates, dilutions of the three strains of cells were prepared with LB broth.
BoHV-1 genomic DNA was extracted using the TIANamp Genomic DNA Kit and Δ gD1 and Δ gD2 fragments were generated by PCR amplification using 2× GoTaq Master Mix under recommended setting. Each PCR product was purified using a Wizard SV Gel and PCR Clean-Up System by agarose gel electrophoresis. The purified PCR product, Δ gD1 or Δ gD2 was sequentially cloned into pET28a double digested by the corresponding restriction endonuclease, followed by transform into competent E. coli DH5α. The recombinant positive plasmid was confirmed by DNA sequencing was designated as pET28a-ΔgD1-ΔgD2.
The purpose of this lab was to observe bacterial mutagenesis of E. Coli by ultraviolet (UV) induced mutation, and observe these mutations with the use of DNA isolation techniques and gel electrophoresis vs. a control. A mutation is the changing in sequence of nucleic acids (1). When restriction endonucleases are added to DNA, the enzyme will read the certain sequence of base pairs that correlate to that enzyme of use, and then will cleave the DNA at the restriction site (2). In mutagenized DNA, the enzyme will be unable to recognize the sequence in which to cut the DNA, and this could be observed with the use of gel electrophoresis by observing the banding patterns of a control vs. the mutagenized (2). The mutagenized may also have less total
A future experiment for site directed mutagenesis/PCR might involve a slightly increased amount of template DNA and primers in the PCR reaction or increased amount of PCR product that is being transformed, in case if the transformation of the plasmid did not work. Another possible change could be done to the PCR thermal cycles, by altering the denaturation and annealing temperatures to a reasonable degree. This is to ensure amplification of the desired plasmid DNA incorporating the desired mutation with accuracy at the appropriate locations within the DNA template. A future experiment for protein expression and purification should be done with further precision. And more care needs to be taken as to include all necessary antibiotics during transformation and expression, depending on the type of plasmids used in the experiment. This is essential to obtain the desired protein containing the appropriate genes to procced with further
In biochemical test, which is base on the hydrolytic catalytic enzyme that show their main similarities between Halo bacterium Salinarum and Haloferax volcanii that focus from its result which show to be as negative that is turn out to be as gelatin and whether it can able to substantiate but it’s not possible as is too difficult to melt it. Concern from its illustration that it is been demonstrate on how negative effect is focus also from casein hydrolysis and from Tween 80 and Tween 20. But in Haloferax mediterranei it show the main difference that its result that show to be as positive but is also turn out on gelatin and how gelatin and casein can able to transform into amino acids that is determine from its source like carbon and other
Genetic transformation occurs when an organism’s genetic makeup is altered due to the introduction of new genetic information which is then incorporated into the organism’s genome. In this lab the pGLO plasmid is introduced into E. Coli bacteria, and incorporates the genes which code for the GFP and beta lactamase to the bacteria’s genome which as a result will be modified. To test the effects of the plasmid, bacteria treated with the plasmid were grown on separate plates, the first containing LB nutrient broth and ampicillin, another containing LB nutrient broth and arabinose and another containing LB nutrient broth, ampicillin and arabinose. Two more plates were grown, one with LB nutrient broth and ampicillin and the other with only the LB broth, using cells that did not contain the plasmid. Since the lab was about genetic transformation, the goal was to find which plate would glow. It was found that the plates that were not exposed to the plasmid did not glow, and the plates containing LB and arabinose and LB, ampicillin and arabinose did glow. The plates containing ampicillin, the antibiotic that kills E. coli did not grow whereas the remaining plates at least had some growth.
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
Isolation of genetically marked of A. flavithermus and B. pumilus was necessary for their manipulation. Spontaneous antibiotic resistant mutants of A. flavithermus and B. pumilus were isolated by increasing the frequency of