Transformation Of Escherichia Coli With pGLO Plasmid
April 24, 2013
ABSTRACT: This experiment focuses on genetic engineering and transformation of bacteria. The characteristics of bacteria are altered from an external source to allow them to express a new trait, in this case antibiotic resistance. In is experiment foreign DNA is inserted into Escherichia coli in order to alter its phenotype. The goal of the experiment is to transform E. coli with pGLO plasmid, which carries a gene for ampicillin resistance, and determine the transformation efficiency. The bacteria are transformed by a combination of calcium chloride and heat shock. When the bacteria are incubated on ice, the fluid cell membrane is slowed and then the heat shock
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Control Plates After Incubation shows whether there was growth of E. coli without the presence of the pGLO plasmid after exposure to ampicillin.
The transformed bacteria showed growth despite the presence of ampicillin (Table 1), whereas the control plate with ampicillin did not show any growth, and the control plate with only LB agar showed the formation of a lawn of bacteria (Table 2). The transformed bacteria on the plate with LB, ampicillin and arabinose differed from the transformed plate without arabinose in that they glowed green under UV light. The bacteria without arabinose maintained an unaltered appearance under UV light. The transformation efficiency for the transformed bacteria was 5.2 × 104 transformants per microgram of DNA.
DISCUSSION: In this experiment the objective was to transform E. coli with the pGLO plasmid and calculate the transformation efficiency. The hypotheses were that the plate with only LB agar and untransformed E. coli would grow a lawn; the control plate of untransformed bacteria with LB and ampicillin would experience no growth; the transformed plate with just LB and ampicillin would grow colonies of bacteria but it would not glow green under UV light; and the transformed plate with LB, ampicillin and arabinose would grow colonies that would glow green under UV light. The results found supported each of these hypotheses as the bacteria grew as predicted. The
Abstract In this lab of transforming bacteria that was experiment today, I will be identifying the process of bacterial genetic transformation and how to calculate transformation efficiency. The samples that will be used in today’s bacteria will contain samples of E.coli sand inserted DNA plasmid into their genetic sequence. If done correctly the results will show a successful genotypic and phenotypic mutations, which will display fluorescent under ultra-violent lights or show signs to being resistant to ampicillin. This experiment was primarily for the purpose of growing E. Coli bacteria.
The color of the bacteria was a whitish color and the colony size is similar both before and after the transformation. The best way to do it is to compare the control of the experimental plates. Cells that were typically not treated with the plasmid could not grow on ampicillin, although cells that were treated with the plasmid can grow on the LB/AMP plate. The plasmid would have to confer resistance to ampicillin. Moving on, the GFP gene is what is glowing in the plate because it was activated by the sugar arabinose. The sugar arabinose and the plasmid DNA are also needed to be present because that is what initially turns on the GFP gene which makes the bacteria glow. Organisms can also turn on and off particular genes for camouflage reasons. An organism would benefit from turning on and off certain
As predicted the E. coli colony transformed with either the PUC18 or the lux plasmid developed an ampicillin resistance. Which made it easier for them to not only survive but also replicate in both the LB agar plates and the LB ampicillin rich agar plate. However the E. coli colony not treated with the plasmids could not survive and colonize in the LB ampicillin rich agar plates. The plate that had no ampicillin in its environment and no plasmid treated E. coli served as a positive control for this experiment because it demonstrated how the E. coli would colonize and grow in a normal setting. The cells in the positive control plate grew into lawn colonies because they were not placed into a selective environment or transformed, so they had no need to acquire ampicillin resistance. Two plates in the experiment contained E. coli cells that were transformed with either the PUC18 or the lux plasmid but were placed in an ampicillin free environment. These two colonies grew
70µL of competent E.coli are added to both test tubes; pUC18 and Lux (Alberte et al., 2012). Both test tubes are then tapped and placed back into the ice bath for 15 minutes. While waiting, another test tube is obtained, filled with 35µL of competent cells and labeled NP for no plasmid. A water bath is preheated to 37 degrees Celsius and all three labeled test tubes are inserted into the bath for five minutes (Alberte et al., 2012). Using a sterile pipet 300µL of nutrient broth are inserted into both the control and Lux test tubes and 150µL are inserted to the no plasmid test tube to increase bacterial growth. All three test tubes are then incubated at 37 degrees for 45 minutes. Six agar plates are obtained and labeled to correspond each test tube, three of the plates contain ampicillin. A pipet is used to remove 130µl from each test tube containing a plasmid and insert it into the corresponding agar plate. For this, a cell spreader is first
The purpose of this experiment was to show the genetic transformation of E. coli bacteria with a plasmid that codes for Green Fluorescent Protein (GFP) and contains a gene regulatory system that confers ampicillin resistance. A plasmid is a genetic structure in a cell that can replicate independently of chromosomes. In this lab, the Green Fluorescent Protein, which is typically found in the bioluminescent jellyfish Aequorea Victoria, was cloned, purified, and moved from one organism to another with the use of pGlo plasmids. It was hypothesized that if bacteria that were transformed with +pGlo plasmids are given the gene for GFP, then transformed cell colonies
The hypothesis above tested the insertion of the pGlo gene to see if the bacteria, E.Coli, will reproduce and grow in the presence of ampicillin and to see if it will cause a green fluorescent glow. (PGLO™ Bacterial Transformation Kit,2017). Based upon the results from this experiment the hypothesis did support the hypothesis and that the presence of the pGlo gene inserted into the E.Coli did cause for growth and fora fluorescent glow to occur. In the experiment, the petri dishes that contained no pGlo (-pGlo) did not show any reproduction nor did a green glow appeared in both dishes. Unlike the two petri dishes, that contained the pGlo gene and ampicillin, the data data showed both reproduction and a glow in the petri dishes.
The plasmid pGLO contains an antibiotic-resistance gene, ampR, and the GFP gene is regulated by the control region of the ara operon. Ampicillin is an antibiotic that kills E. coli, so if E. coli, so if E. coli cells contain the ampicillin-resistance gene, the cells can survive exposure to ampicillin since the ampicillin-resistance gene encodes an enzyme that inactivates the antibiotic. Thus, transformed E. coli cells containing ampicillin-resistance plasmids can easily be selected simply growing the bacteria in the presence of ampicillin-only the transformed cells survive. The ara control region regulates GFP expression by the addition of arabinose, so the GFP gene can be turned on and
This experiment was designed to test and observe the transformation efficacy of the pUC18 and lux plasmids in making E. coli resistant to ampicillin. Both plasmids code for ampicillin resistance, however, the lux plasmid codes for a bioluminescence gene that is expressed if properly introduced into the bacteria’s genome. The E. coli cultures were mixed with a calcium chloride solution and then heat shocked, allowing the plasmids to enter the bacteria and assimilate into the bacterial DNA. The plasmids and the bacteria were then mixed in different test tubes and then evenly spread onto petri dishes using a bacterial spreader, heating the spreader between each sample to make sure there is no cross contamination. Each of the dishes was labeled and then incubated for a period of 24 hours. The results were rather odd because every single one of the samples grew. Several errors could have occurred here, cross contamination or possibly an error in preparation as every single sample in the class grew, meaning all samples of the bacteria transformed and became ampicillin resistant.
The purpose of this lab is to use genetic engineering to transform E. coli bacteria by inserting the plasmid pGLO, and to then see if the bacteria was transformed by using the antibiotic, ampicillin.
This pBlu lab had for purpose to present the changes of the strain of E. coli bacteria due to new genetic information being introduced into the cell. In this experiment we are freezing and heat shocking the E. Coli bacteria that is then forced to take the plasmid DNA. The E. coli then transforms the pBLu plasmid, which carries the genes coding for two identifiable phenotypes. After following the Carolina Biological steps our lab worked well and we able to see some colonies of bacteria on the plates. The x-gal plate showed a significant amount of bacteria to confirm that the pBlu plasmid took over the E. coli strain.
In the pGLO Bacterial Transformation lab, Escherichia coli is transformed with a gene encoding green fluorescent protein by inserting a plasmid containing the GFP gene, beta-lactamase, and arabinose into the bacterium. Successfully transformed bacteria will grow in the presence of ampicillin and glow a bright green color under ultraviolet light. The sugar arabinose is responsible for switching on the GFP gene in the transformed cells, without it, the gene will not be expressed.
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 plate with the bacteria that is most like the original non-transformed E. coli colonies is the LB/-pGLO plate. The bacteria could grow because there was no ampicillin on the plate, and it couldn’t have been transformed because no pGLO was added. Since the plasmid wasn’t added and the environment was ampicillin free, the bacteria on the LB/-pGLO plate should be pretty much the same as the original E. coli because nothing was done to it.
This experiment was performed to test the hypothesis if LB nutrient broth, +pGLO and -pGLO Ampicillin, and Arabinose was placed in the E. coli plates, then there will be a significant growth in the newly transformed bacteria and it will possess the ability to glow under UV light. The measurements were recorded from the bent glass tube in each glass test tube. The transformation protocol tested for the newly possessed traits in E.coli bacteria. Throughout the experiment there were many probable reasons for failure. If the pipettes and sterile loop were not thrown out in between each use, a cross contamination could cause a miscalculation in the experiment causing the data results to fail. The hypothesis that was tested was validated due to the positive results with each experiment stating that newly transformed organisms due in fact pass on traits.
Ampicillin inhibits bacterial growth by preventing the synthesis of the E. coli cell walls, resulting in cell death (The Biotechnology Education Company, 2003; Bruce Roe, n.d.). When the ampicillin resistance gene is present, it directs the production of an enzyme which blocks the action of ampicillin. Therefore, when the transformation liquid is placed on an ampicillin agar plate, the E. coli cells which reject the plasmid will not be able to block the effects of ampicillin, and therefore, will not be able to grow on the plate (The American Phytopathological Society, 2016).