Objective:
Use techniques such as electrophoresis and restriction mapping to understand the concepts of DNA digestion. Also, become familiarized with restriction enzymes and double digestion.
Results:
The electrophoresis of digested phage lambda DNA is shown in the picture below. DNA has a negative charge and will attract to the positive pole at the end of the gel. The bands in each lane represent different sized DNA fragments. The closest band to the wells represent longer fragments because they can’t travel as fast. The farther away from the well, closer to the positive pole, are smaller fragments of DNA. The farthest lane to the left is the ladder, used to compare different sized fragments. EcoRI has one very distinct band at the beginning
Digestion of the haemolytic and non-haemolytic cells allowed for easier identification of fragments during electrophoresis analysis. Lane 12 in figure 3 show the size markers of SPP1 digested with EcoR1 while lanes 6 and 7 show samples of pK184hlyA and pBluescript digested with EcoR1 and Pst1. Lane 4 was loaded with plasmid DNA from haemolytic cells digested with EcoR1 and Pst1 while lane 5 was loaded with EcoR1 and Pst1 digested DNA from non-haemolytic cells. There was a lack of technical success in both lanes due to no bands appearing in lane 4 and only a single band appearing in lane 5. Theoretically, two bands should appear in both lanes after successful to allow for fragment identification. A possible explanation for the single, large fragment in lane 5 is that successful digestion did not take place and the plasmid was only cut at one restriction site leaving a large linear fragment of plasmid DNA. The absence of bands in lane 4 could be because there was not enough plasmid loaded into the lane. Another possibility could be that low plasmid yield as obtained when eluting the experimental samples in order to purify it. Lanes 8 and 9 belonged to another group and show technical success as two bands were present in both the haemolytic (lane 8) and non-haemolytic (lane 9) lanes. If the
The affects of pH, temperature, and salt concentration on the enzyme lactase were all expected to have an effect on enzymatic activity, compared to an untreated 25oC control. The reactions incubated at 37oC were hypothesized to increase the enzymatic activity, because it is normal human body temperature. This hypothesis was supported by the results. The reaction incubated to 60oC was expected to decrease the enzymatic activity, because it is much higher than normal body temperature, however this hypothesis was not supported. When incubated to 0oC, the reaction rate was hypothesized to decrease, and according to the results the hypothesis was supported. Both in low and high pH, the reaction rate was hypothesized to decrease, which was also supported by the results. Lastly, the reaction rate was hypothesized to decrease in a higher salt concentration, which was also supported by the results.
As the solution pH can influence the stability of NaClO-NH3 blend and the elimination of SO2, NOx, the impact of the pH of NaClO-NH3 blend solution on the instantaneous removal as well as the duration time was investigated, and the final pH after reaction was also detected and shown in Fig. 5. It can be seen that the variation of solution pH has a negligible effect on the desulfurization, but the elevated pH has a great promotion on the NOx removal, the efficiencies are significantly increased from 36% to 99% for NO2 in the pH range of 5–12 and from 19% to 65% for NO when the pH is between 5 and 10, after where, both of them are constant. Hence, the optimal pH of the NaClO-NH3 solution for the
in the sample in to many identical samples. The DNA retrieved from the reaction can then be
Many things have impacted both the Science and Medical fields of study. Electrophoresis and DNA Sequencing are two of these things. Together they have simultaneously impacted both of these fields. On one hand, there is Electrophoresis. Electrophoresis is a specific method of separating molecules by their size through the application of an electric field. It causes molecules to migrate at a rate and distance dependent on their size. On the other hand, there is DNA Sequencing. DNA Sequencing is a technique used to determine the exact sequence of bases
Planaria are one of many free-living flat worms that can be found in marine, aquatic, and terrestrial environments. Certain characteristics of planaria worms include an acoelomate body, a gut with no anus, lack of a blood vascular system, and a simple nervous system. The main reason as to why planaria are subjected to many studies is because of their unique ability to regenerate. Regeneration is the ability to re-grow lost body parts that may have been cut off. This is possible because the organism has the ability to form a blastema, which is an accumulation of undifferentiated cells, at the site of the wound. Regeneration is capable of occurring at various degrees throughout the animal kingdom. This unique process would never be able to be seen in human beings. Humans and other mammals
In biology class, we were learning about enzymes. Enzymes are proteins that help catalyze chemical reactions in our bodies. In the lab, we were testing the relationship between the enzyme catalase and the rate of a chemical reaction. We predicted that if there was a higher percentage of enzyme concentration, then the rate of chemical reaction would increase or it would take less time. We placed 1 ml of hydrogen peroxide into four depressions. Underneath the first depression, we place 1 ml of 100% catalase and make 50% dilution with 0.5 ml of water. We take 50% of that solution and dilute with 0.5 ml of water and we repeat it two more times. there were four depressions filled with catalase: 100%, 50%, 25% , 12.5 % with the last three diluted
The two modes of analysis that will be used to identify an unknown insert piece of DNA would be plating the transformation cells onto LA plates that have either ampicillin or chloramphenicol and PCR. We will use the PCR thermocycler to denature the restriction enzymes that were specifically used to assimilate the vector DNA. It is important to use the PCR thermocycler because denaturation of the restriction enzyme will prevent the restriction enzyme from cutting the vector DNA, after the insert DNA has assimilated to the vector DNA. After the addition of specific primers that complement the base pair to its corresponding target strand, PCR will be used. Subsequently, Taq polymerase will be used to determine whether the insert DNA has been properly assimilated to the vector DNA. Within this specific situation, the target strand will be the insert DNA. After we let the PCR thermocycler run for approximately 2 ½ hours, we will then put our PCR products in the gel and run the gel to completion. After the gel has run to completion, we will then take a photograph of the gel using the UV transilluminator with the assistance of our TA. If the insert DNA was properly assimilated to the vector DNA, then our corresponding gel photo would have one band. After the cells have been transformed, we would g...
...l electrophoresis (SCGE) also known as comet assay has become one of the standard methods for assessing DNA damage, with applications ranging from testing genotoxicity, human bio-monitoring and molecular epidemiology to its use in fundamental research in DNA damage and repair (Collins, 2004). The comet assay is a simple method for detecting DNA strand breaks within cells in eukaryotes. The procedure of comet assay includes Embedding the cells in agarose in a microscope slide, followed by lysing of cells with detergent and high salts to form nucleotides containing supercoiled loops of DNA linked to the nuclear matrix, and then undergoing Electrophoresis at high pH, which results in formation of structures resembling as comets, observed by fluorescence microscopy. The intensity of the comet tail relative to the head reflects the number of DNA breaks (Collins, 2004).
Modern techniques , rather than the gene map , maps the map of the DNA within the gene itself : the positions of short sequences " marker " are used as markers signaling over the cromosssomas . Once a gene is discovered, it is necessary to unravel its base sequence prior to its function being studied . The sequencing has become easier with the development of methods for cloning the DNA - producing large amounts of identical fragments. In the method most widely used DNA sequencing , the chain is denatured into single strands . These are then used as templates for DNA synthesis , but such that replication to as the double helix reaches a certain growth in the mold base . In addition to provide DNA polymerase and the four bases, A - G -C- T, also using small amounts of these dideoxynucleotide bases. This is incorporated , as the normal bases, the double helix growth but prevent the continuation of the chain. The fragments are then separated by gel electrophoresis and the base seq...
Lyons, R.H. (2004). How do we Sequence DNA? In A Primer in DNA Structure and Function. Retrieved from http://seqcore.brcf.med.umich.edu/doc/educ/dnapr/sequencing.html
Gene cloning works by first isolating the desired gene and ‘cutting’ it from the original chromosome using restriction enzymes. The piece of DNA is ‘pasted’ into a vector and the ends of the DNA are joined to the vector DNA by ligation. The vector is introduced into a host cell, often a bacteria or yeast, by a process called transformation. The host cells copy the vector DNA along with their own DNA, creating multiple copies of the inserted DNA. The vector DNA is separated from the host cells’ DNA and purified.
Agarose gel electrophoresis separates molecules by to their size, shape, and charge. Biomolecules such as DNA, RNA and proteins, are some examples. Buffered samples such as glycerol and glucose are loaded into a gel. An electrical current is placed across the gel. The current moves the molecules towards the cathode or anode. The speed of the moving molecules depends on the size, shape, and charge. The properties of the gel will definitely affect the movement. Small molecules are expected to move easily and faster thru the pores.
Gel electrophoresis is used in a variety of settings, particularly in molecular biology. Besides being used to separate nucleic acids, such as DNA and RNA, gel electrophoresis is also employed to divide proteins (Gel Electrophoresis). According to research, electrophoresis is applied for the following reasons, "To get a DNA fingerprint for forensic pur...
Secondly the gene has to be cut from its DNA chain. Controlling this process are many restriction endonucleases (restriction enzymes). Each of these enzymes cut DNA at a different base sequence called a recognition sequence. The recognition sequence is 6 base pairs long. The restriction enzymes PstI cuts DNA horizontally and vertically to produce sticky ends.