Restriction Analysis
Hayley Keller
Biochemistry Laboratory: BIOL 2324
TA: Manasa Madasu
Date Performed: July 14th, 2015
Date Due: July 21st, 2015 Introduction:
Restriction digest involves the use of restriction enzymes (also known as restriction endonucleases) to locate specific base pair sequences in DNA. These enzymes cut, or cleave, DNA only at their designated sequence, which is referred to as a recognition sequence. While there are four different types of restriction enzymes (1), the only type that was worked with in the following experiment were type II restriction enzymes (2). These enzymes have recognition sites that are mostly palindromic and usually consist of around four to eight base pairs. They also require only magnesium (Mg2+) as a cofactor to operate. Cofactors are molecules that bind to enzymes in order to activate them (3). Additionally, they cut DNA only at, or very near to, their specified restriction site, unlike other types, which cleave at various distances from their recognition site (1). The restriction enzymes that will be used in following experiment are Hind III, PVU II, and Bgl I (2). Hind III recognizes and cuts DNA at the sequence AAGCTT. It is isolated from Haemophilus influenzae (4), which is a bacteria that is the cause of several diseases, including pneumonia, and meningitis. (5) When Hind III is used to cleave DNA, the end result will have “sticky ends,” which means that there will be a few unpaired nucleotide bases on each end of
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).
We were using a restrictive enzyme to cut the DNA into smaller fragments. For the restriction digest we pipet 4 micrometers of enzyme mix into the bottom of each of our colored tubes making sure to use a new tip for each sample. Next, we capped the tubes and mixed the contents by flicking the tube a little bit with our fingers. After we mixed the contents, we tapped the tube to make sure all the liquid would go to the bottom of the tube. Then, we put the colored tubes in the heating blocks and we let them incubate for 35 minutes at 37 degrees Celsius.
Find out more about restriction enzymes by viewing the animation and reading the article listed below.
How to determine where the restriction enzymes, Ava II and Pvu II, sliced the DNA.
By restriction enzymes then amplified by polymerase chain reaction to make many to millions of copies of a single fragment.
This however, was unsuccessful, as the restriction digestion created fragments of many different lengths, resulting in smears at different lengths on the gel electrophoresis due to the restriction enzyme recognition sites being present in-between the telomeric repeat sequences, the analysis was thus
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
The chromosomal DNA was digested with different dilutions of Bam H1 (10units/µl). The reaction mixture consisted of 10 g of chromosomal DNA and 10 l of the restriction enzyme buffer in a final volume of 100 l. In the first PCR tube 20 l of the reaction mixture was dispensed while 10 l was dispensed in 2 to 7 PCR tubes. The tubes were placed on ice for 2 mins and 10 units of the Bam H1 were added to the first tube. The contents were mixed and 5 l from the first tube was transferred to the second tube.
This strategy can be employed to study enzymes from other Gram-positive organisms with ease. It
(2012) introduced a new genetic technique that was derived from the defense mechanisms of bacteria. Some bacteria use a CRISPR-Cas system to defend against foreign viral and plasmid genetic material. Once foreign targets enter the system, the bacteria will integrate its CRISPR array to parts of the nucleotide sequences on the invading sequence. The bacteria will then produce a precursor CRISPR-RNA that complements the invading sequence, and is used to find all foreign sequences that match it. These precursor RNAs will work with Cas proteins to cleave the foreign sequence, thus effectively silencing it. There are multiple types of CRISPR-Cas systems that bacteria use. Type 2 systems, paired with Cas-9, use another RNA sequence, tracrRNA (trRNA), as a complement to precursor CRISPR-RNA. These systems used both trRNA and precursor CRISPR-RNA to induce a double stranded cleave. After this discovery, a Cas9 protein was purified and tested to see if it would be able to cleave DNA. It was discovered that if both a trRNA and a precursor CRISPR RNA were present with complementary sequences to a sequence in a DNA strand, the result would be a double strand cleave in the DNA. Cas9 also contains two domains, each of which only cleave either the complementary or the non-complementary strand of the target DNA. After looking at both the trRNA and the precursor CRISPR RNA, researchers theorized that they could engineer a chimera RNA that combined certain sequences of both
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.
Within a genome, there is a vast sequence of DNA that may be studied. The resulting goal of this study is to create a genomic library of the bacteria Aliivibrio Fischeri. We will be achieving this purpose by making Escherichia Coli luminescence through the use of the lux operon. In the process of understanding the genomic library of A. Fischeri bacteria, we will be creating a restriction map of the restriction sites in the plasmids containing a lux.
The chemical and reagents used for the extraction and quantitation of DNA were: Plant DNAzol (0.3ml/0.1g), 100% ethanol (100%: 0.225 ml/0.1 g, 75%: 0.3 ml/0.1 g), Chloroform (0.3 ml/0.1 g), Plant DNAzol-ethanol solution: Plant DNAzol, 100% ethanol (1:0.75 v/v), TE buffer (10 mM Tris, 1 mM EDTA pH 8.0), 1.2% agarose gel (Agarose, 1X TAE buffer), 6X loading buffer (glycerol, Tris/EDTA pH 8.0, ethidium bromide), .25X TAE buffer, Restriction enzymes and Restriction endonuclease buffers. All the chemicals used were quality grade. The restriction
Enzymes are applied to DNA to break it into smaller pieces which are called restriction endonucleases. These restriction endonucleases become
Did you know that with the science of DNA manipulation, animal cadavers can be turned into insulin for diabetics? Back in the 80's scientists isolated the human gene for insulin and transferred it into bacteria. Now bacteria cultures are used to produce large amounts of human insulin. DNA manipulation is especially important in medicine, where it holds the hope of curing genetic diseases such as Huntington's, and even some types of cancer. There are several major types of DNA-manipulation enzymes used by living cells. The first type is DNA polymerase, which cells use to replicate their own DNA. The next type is DNA ligase, which joins 2 pieces of DNA to create a single piece. The third type is restriction enzymes, which appear to be made only by bacteria. Restriction enzymes are very important enzymes that are vital to our manipulation of DNA (Rapoza, DNA, 2).