The experiment is to identify the guilty suspect that is present at the crime scene by comparing with the DNA samples. Polymerase Chain Reaction(PCR) is used to amplify the small amount of Deoxyribonucleic Acid (DNA) for forensic or genetic studies, which require necessary product and placed in the thermal cycle. Gel electrophoresis is being run in order to analyze and compare the DNA samples at the crime scene with the guilty suspects.
Gel electrophoresis is used to separate DNA using an electric current applied to the gel matrix, which causes the DNA samples to move towards the positive charge.
The results obtain from the gel electrophoresis able to concluded the which suspect have been at the crime scene by analyzing against the …show more content…
PCR and gel electrophoreses usually enable to identify a crime suspect by comparing the DNA among all the suspects with the amplified DNA found in crime scene evidence.
One of the main reason PCR is usually being used often, because of its simplicity and specificity. It allows to target and amplify one specific segment of DNA with a few hundreds of the base pairs in length out of a complete genome of over 3 billion base pairs.
The requirement for PCR are as follows: One strand of DNA template strand, Taq polymerase, Buffer solution, 2 Primers (Forward and reverse primers), Deoxyribonucleic Triphosphate (dNTPs) and Divalent cations (Mg2+). Once PCR is performed gel electrophoresis is required to be done, to allow each sample of the crime suspects base pairs to be compared.
Gel electrophoresis usually used to help separate DNA or other protein molecules by using electric current that is being applied to the gel. DNA is negatively charged hence electric current it is usually to …show more content…
This causes the double-stranded DNA to melts and separates into two pieces of single- stranded DNA due to the breakage of weak hydrogen bonds. Annealing is usually set at the temperature of 45-68oC, which the primers pair up and bind to the correct parts of the single-stranded DNA template. Lastly, extension step allows the enzymes DNA to bind the correct nucleotides to make a double-stranded DNA molecule. PCR usually repeats for around 30 cycles.
Phase two of the experiment is to prepare the gel electrophoresis apparatus. Five PCR tubes were obtaining from the previous that had been in the thermal cycler and place it on the ice. 4μl of 6x UView loading dye is being transferred to each of the PCR tubes and placing the pipette downwards in order for the dye to mix with the samples. Loading dye is requiring to be used to add density to the PCR samples and allowing it to sink into the gel.
Agarose gel is required to be placed in the electrophoresis apparatus and ensure that the well of the gel is being placed near the black (-) electrode and the base of the gel near to the red (+) electrode. It is important to place it at the correct position or it would move in a wrong way and causes the DNA to leak into the buffer