Transformation of Escherichia coli in different concentrations of Plasmid DNA
Introduction
This report discusses an experiment which students have to transform and plate competent Escherichia coli in different concentrations of plasmid DNA. This experiment uses four concentrations of plasmid DNA to perform four transformations. These concentrations are namely, 5 µl of distilled water, which acts as the control in this experiment; 2.5 µl of undiluted plasmid DNA; 1.0µl of undiluted plasmid DNA; and lastly, 1.0µl of plasmid DNA diluted 1 in 10. Transformation is an important aspect in genetic engineering as it allows for a particular DNA to enter into another cell. The aim of this experiment is to be able to perform a cell transformation
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Then, we placed 100 µl of the E. coli cells into four Eppendorf tubes each and labelled them A, B, C and D. After filling them up, we placed them into an ice box. After this, we needed to perform the transformation process by mixing the E. coli cells with different concentrations of plasmid DNA. In test tube A, we added 5 µl of distilled water to the E. coli cells. In test tube B, we added 2.5 µl of undiluted plasmid DNA to the E. coli cells. In test tube C, we added 1.0 µl of undiluted plasmid DNA to the E. coli cells. Lastly, in test tube D, we added 1.0 µl of plasmid DNA diluted 1 in 10 to the E. coli cells. Then, we used a P100 pipette and mixed all the liquids in all the Eppendorf tubes by pipetting the solution up and down. Then, we left the Eppendorf tubes along with its contents in the ice box for twenty minutes. After twenty minutes, we labelled the base of the four agar plates to match with the appropriate plasmid DNA concentration about to be plated. We also wrote our initials, the date, and the table number on the base of the agar plate. We then gently lifted up the cover of the agar plate with just enough space to allow us to plate each tube of cells onto four different agar plates – one agar plate to one plasmid DNA concentration. We used a spreader to spread the cells evenly over the surface of the agar, being careful not let the spreader touch
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.
In order to find transformation efficiency, the total number of colonies on the plate is divided by the total amount (µg) of DNA spread on the plate. All the factors that must be taken into account while finding the transformation efficiency include; the total amount (µg) of plasmid DNA used, the total volume (µl) of cell suspension prepared, the fraction of DNA spread on the plate and finally the total amount (µg) of DNA present on the plate. In the LB/AMPC plate the transformation efficiency was 8.2 x 103 colonies per µg of plasmid DNA while the LB/AMPlux plate the transformation efficiency was 1.07 x 104 colonies per µg of plasmid DNA. The transformation efficiency for the LBC and LBlux plates were not taken into account, even though they too transformed because they were not in a restrictive environment where they needed to express their ampicillin resistance genes in order to
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
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
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.
This lab is about moving genes from one thing to another using plasmids. Plasmid has the ability to replicate, so it replicates independently, and separately from the chromosomal DNA. Plasmid are one or more small piece of DNA and they enter cells as a double strand DNA. When they enter the cell as a doubke strand they do not invade he chromosomal DNA. We will also transform bacteria into GFP which is mainly from the jelly fish Aequorea Victoria. The GFP causes the the jelly fish to fluorescent and glow in the dark. After the transformation, bacteria starts to make the GFP which causes them to glow a green color under a ultraviolet light.
The purpose of this experiment is to make E.Coli competent so that it can be transformed in order to become immune to ampicillin, then we would be able to determine the transformation efficiency of the culture. We determine this by preparing 4 plates of E.coli, each labeled “LB-plasmid”, “LB+plasmid”, “LB?Amp-plasmid”, and “LB/Amp+plasmid”. This meant that either should have lacked plasmid and Ampicillin, with plasmid but lacked Ampicillin, without plasmid but with Ampicillin, or were with Ampicillin and plasmid, respectively. Then we made the bacterial cells competent by adding CaCl2 to 2 vials of the colony (one with plasmids), and incubating on ice, then heat shocking, and returning to ice. Luria Broth is then added and left to sit for 5-15
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.
Spin the two tubes in a centrifuge for 5 minutes on opposite side of the centrifuge. The bacterium will collect at the bottom of the tube, so pour out the extraneous supinate. Then, add 250 microliters of buffer. The Ca2+ cation of the buffer neutralizes the repulsive negative charges of the phosphate backbone of the DNA and the phospholipids of the cell membrane allowing the DNA to pass through the cell wall and enter the cells. Place both tubes on ice. Then add 10 microliters of water into one tube and 10 microliters of plasmid DNA into another tube labeling the one with DNA with a + and the one with water -, and place on ice for 10 minutes.
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.
To do a transformation one micro test tube was labeled +pGLO and the other was labeled –pGLO, using a transfer pipette 250 µL of transformation solution was added to each tube in the foam rack. The tubes were then placed on ice for three minutes. During these three minutes, a sterile loop was used to pick up a single colony of E. Coli from the starter plate by gently running the loop over the agar. This loop was then inserted into the +pGLO tube and the loop was spun until the entire colony dispersed. Using a different sterile loop, the same procedure was used for the –pGLO tube. After both tubes had their own colony of E. Coli, they were placed on ice for another three minutes. DNA plasmid was added to the +pGLO tube by taking a new sterile loop and immersing it into the stock tube creating a film across the loop then inserting
For this experiment, E. coli was best for genetic engineering because of their size, and their fast reproduction (Spilios, 2017). E. coli will be genetically transformed using an engineered plasmid. A plasmid is a circular piece of DNA which independently replicates and multiplies because it has its own origin of replication (Spilios, 2017). The pGLO is the plasmid used in this experiment. Plasmids are used as vectors and they contain manipulated genes such as genes coding for antibiotic resistance for drugs like ampicillin. This antibiotic resistance of such serves as the selectable marker in genetic transformation and for genetic transformation to proceed, the cell must reach competency which is the physiological state that is required for the vector plasmid to get into the cell for transformation (Spilios, 2017). While competency can be reached naturally in some organism, it must be reached artificially in E. coli through treatment with CaCl2 and exposing them to heat shock using incubation (Spilios, 2017).
Based on the experiment results and the data obtained, this experiment showed that the predicted results were accurate. It is possible to produce a bacterial transformation of the genes of the bacteria E. Coli by the inoculation of a p-GLO plasmid. The bacterial transformation produced a change in the bacterial genome showing a change in the phenotype of the bacteria, by acquiring the traits of the genes introduced into the plasmid. In this experiment, each of the four plates had LB broth for nutrients and a bacterial suspension of E. Coli to study its reaction in the presence of the antibiotic ampicillin and the p-Glow plasmid. In the control plates, labeled as # I for LB/-pGLO, and # II for LB/-pGLO/
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