We went to the life centre to carry out PCR. We did this to investigate what our PTC genotype would be. To do this we had to carry out the following steps: DNA extraction, PCR and gel electrophoresis. I found that my genotype matched my phenotype, showing that I was a PTC taster and my genotype was hetero zygote taster.
DNA extraction
DNA is removed from human cells for a range of reasons. With a pure sample of DNA you can test for a genetic disease, analyze forensic evidence, or study a gene involved in cancer. DNA extraction is an important part of the process because the DNA first needs to be purified away from proteins and other cellular contaminants. To extract cells from the cheeks, we have to burst cells open to release DNA and then …show more content…
PCR is used every day to diagnose diseases, identify bacteria and viruses, match criminals to crime scenes, and in many other ways. In a PCR experiment, two primers are planned to match to the segment of DNA you want to duplicate. Through matching base pairing, one primer attaches to the top strand at one end of your segment and the other primer attaches to the bottom strand. In most cases, 2 primers that are 20 or so nucleotides long will target just one place in the entire genome. We put our extracted DNA into a pcr tube to begin this process. We then added primer to the pcr tube. We also added nucleotides. The last thing we added to the pcr tube was DNA polymerase. This reads the DNA code. DNA polymerase is selected as it can withstand the heat of the pcr reaction. The pcr tube is then put into a thermal cycler. This can accurately heat and cool the tube which having the right temperature is crucial for the reaction to work. The first cycle begins, this is when the double helix separates, creating two single strands of DNA. Primers crowd their way in and lock onto their target before strands rejoin. Complementary nucleotides are then added onto a single strand. It continues until it gets to the end and then falls off. Temperature is raised again to separate the DNA strands in cycle two. When the temperature lowers, primers attach. The strand is then …show more content…
It sorts DNA strands according to length. The gel is the part that sorts the DNA. We put DNA in the holes at one end of the gel. Electrophoresis is the term used for describing how we push the DNA through the gel. An electric current is added to make the DNA move. Short strands move through the holes more quickly than longer strands. DNA strands the same length move at the same speed and end up getting grouped together. The samples sort themselves because of this. Staining the DNA makes it visible in the gel. We see large groups of DNA stained on the gel because they show up as bands. The melted agarose mixture gets poured into the mold and the gel is then left to cool and solidify. Tiny holes form as the gel cools. Buffer is added into the electrophoresis box and the gel also gets added. The buffer controls the electric current from one end of the gel to the other. It also makes sure the gel doesn’t dry out. A micropipette is used to suck up some loading buffer which is then added to the DNA sample. We then transfer the DNA sample into the gel using the micropipette. We then suck up some DNA size standard and put it into the next wall in the gel. The lengths of strands are known in this so it is used as a reference to estimate the lengths of DNA strands in the sample. Electricity is then switched on. The black end generates a negative charge and the red end will generate a positive charge. The current will be passed
DNA extraction
DNA is removed from human cells for a range of reasons. With a pure sample of DNA you can test for a genetic disease, analyze forensic evidence, or study a gene involved in cancer. DNA extraction is an important part of the process because the DNA first needs to be purified away from proteins and other cellular contaminants. To extract cells from the cheeks, we have to burst cells open to release DNA and then …show more content…
PCR is used every day to diagnose diseases, identify bacteria and viruses, match criminals to crime scenes, and in many other ways. In a PCR experiment, two primers are planned to match to the segment of DNA you want to duplicate. Through matching base pairing, one primer attaches to the top strand at one end of your segment and the other primer attaches to the bottom strand. In most cases, 2 primers that are 20 or so nucleotides long will target just one place in the entire genome. We put our extracted DNA into a pcr tube to begin this process. We then added primer to the pcr tube. We also added nucleotides. The last thing we added to the pcr tube was DNA polymerase. This reads the DNA code. DNA polymerase is selected as it can withstand the heat of the pcr reaction. The pcr tube is then put into a thermal cycler. This can accurately heat and cool the tube which having the right temperature is crucial for the reaction to work. The first cycle begins, this is when the double helix separates, creating two single strands of DNA. Primers crowd their way in and lock onto their target before strands rejoin. Complementary nucleotides are then added onto a single strand. It continues until it gets to the end and then falls off. Temperature is raised again to separate the DNA strands in cycle two. When the temperature lowers, primers attach. The strand is then …show more content…
It sorts DNA strands according to length. The gel is the part that sorts the DNA. We put DNA in the holes at one end of the gel. Electrophoresis is the term used for describing how we push the DNA through the gel. An electric current is added to make the DNA move. Short strands move through the holes more quickly than longer strands. DNA strands the same length move at the same speed and end up getting grouped together. The samples sort themselves because of this. Staining the DNA makes it visible in the gel. We see large groups of DNA stained on the gel because they show up as bands. The melted agarose mixture gets poured into the mold and the gel is then left to cool and solidify. Tiny holes form as the gel cools. Buffer is added into the electrophoresis box and the gel also gets added. The buffer controls the electric current from one end of the gel to the other. It also makes sure the gel doesn’t dry out. A micropipette is used to suck up some loading buffer which is then added to the DNA sample. We then transfer the DNA sample into the gel using the micropipette. We then suck up some DNA size standard and put it into the next wall in the gel. The lengths of strands are known in this so it is used as a reference to estimate the lengths of DNA strands in the sample. Electricity is then switched on. The black end generates a negative charge and the red end will generate a positive charge. The current will be passed