Search results
Results From The WOW.Com Content Network
For example, the positive charge of ethidium bromide can reduce the DNA movement by 15%. [12] Agarose gel electrophoresis can be used to resolve circular DNA with different supercoiling topology. [16] DNA damage due to increased cross-linking will also reduce electrophoretic DNA migration in a dose-dependent way. [17] [18]
The negative charge of its phosphate backbone moves the DNA towards the positively charged anode during electrophoresis. However, the migration of DNA molecules in solution, in the absence of a gel matrix, is independent of molecular weight during electrophoresis, i.e. there is no separation by size without a gel matrix. [12]
DNA gel electrophoresis is usually performed for analytical purposes, often after amplification of DNA via polymerase chain reaction (PCR), but may be used as a preparative technique prior to use of other methods such as mass spectrometry, RFLP, PCR, cloning, DNA sequencing, or southern blotting for further characterization.
DNA exists in many possible conformations that include A-DNA, B-DNA, and Z-DNA forms, although only B-DNA and Z-DNA have been directly observed in functional organisms. [14] The conformation that DNA adopts depends on the hydration level, DNA sequence, the amount and direction of supercoiling, chemical modifications of the bases, the type and ...
Addition of an acetyl group, which carries a negative charge, effectively removes the positive charge and hence, reduces the interaction between the histone tail and the nucleosome. [18] This opens up the usually tightly packed nucleosome and allows transcription machinery to come into contact with the DNA template, leading to gene transcription.
A codon table can be used to translate a genetic code into a sequence of amino acids. [1] [2] The standard genetic code is traditionally represented as an RNA codon table, because when proteins are made in a cell by ribosomes, it is messenger RNA (mRNA) that directs protein synthesis. [2] [3] The mRNA sequence is determined by the sequence of ...
The DNA fragments are transferred out of the gel or matrix onto a solid membrane, which is then exposed to a DNA probe labeled with a radioactive, fluorescent, or chemical tag. The tag allows any DNA fragments containing complementary sequences with the DNA probe sequence to be visualized within the Southern blot. [1]
Electrophoresis is the basis for analytical techniques used in biochemistry for separating particles, molecules, or ions by size, charge, or binding affinity, either freely or through a supportive medium using a one-directional flow of electrical charge. [10] It is used extensively in DNA, RNA and protein analysis. [11]