Question

Please post a lab report for analyzing the plasmid DNA extracted

Answer 1

Lab report for analysis of extracted plasmid DNA.

Introduction:
DNA molecules can be separated by agarose gel electrophoresis which separates DNA molecules on the basis of their shape and size .Agarose gel have certain interesting characteristics such as it is chemically inert,stable and hydrophilic and that is the reason it is widely used for electrophoresis techniques.
The range of sizes of the DNA molecule that can be separated in the gel depend on the pore size of the gel which in turn is dependent on the concentration of agarose.
On application of electric field, DNA molecules being negatively charged will migrate towards the anode.So the wells where the DNA samples are to be loaded must be towards the cathode and the gel is placed accordingly in the electrophoresis tank.

Procedure:

• Ethidium bromide(an intercalating agent of DNA) is added to the agarose gel before placing the gel in electrophoresis tank.
• The gel is then placed in the electrophoresis tank and layered with buffer solution.
• Loading buffer is added to the plasmid DNA samples.Glycerol and a loading dye is present in the loading buffer.Glycerol increases sample density and loading dye helps us to track the migration of DNA in the gel.
• DNA samples are loaded into the wells along with DNA molecular weight markers.
• Electric field is applied and migration of DNA is tracked.
• The gel contains the stained DNA molecules separated on the basis of their sizes and the bands can be detected in an UV-transillumination apparatus.

Discussion:
The plasmid DNA molecules are separated on the basis of their size as well as shape in agarose gel.The bands of low molecular weight migrate faster and appear at a lower position in the gel(towards the anode) and the heaviest band of highest molecular weight appear at a lower position in the gel.The results are shown in the diagram.

DNA CL2 (low mobility Dixechon DNA mode sa nblt) high mobil