Dna Extraction

Extraction of DNA

By: Hoang Thong Summat (Jason)

Lab partner: Christian
Materials and Method : please see week 1 on Moodle

Result

As we can see in the picture, the extracted DNA appears to be cloudy and white solid.

[pic 1][pic 2]

Questions

1. Strawberries are polyploid, which means they have more chromosome diploid organisms. For further explanation, they are multicellular and octoploid, it means they have 8 copies of their chromosomes in each of cell. Therefore, strawberries are good source of DNA

1. We smashed strawberries to break down the cell wall, cellular and nuclear membrane. The most important thing that we aim to break down is the nuclear membrane because chromosomes are found in the nucleus of a cell and each chromosome is made up of DNA tightly coiled many times around proteins called histones. Therefore, after smashing the strawberries, their DNA and cell contents are released so we can easily isolate the DNA.

1. There are some possible reasons:

• The volume of the fluid or alcohol used is not the same

• The amount of strawberries provided is less or greater than other groups.

• The strawberries are not full smashed by each group.

1. We use soapy salty water because firstly, soap can dissolve phospholipid the in cell and secondly, in salty water we have NaCl (Na+ and Cl-) which is fully charged. As we have known, DNA’s structures are used to make proteins, DNA has negative charged and proteins are positive charged, with NaCl we can easily separate DNA and Proteins. Therefore, we can continue our next step to make the DNA more clearly to appear.
2. DNA is insoluble with isopropyl alcohol. In addition, insoluble means incapable of being dissolved.

1. DNA is not soluble in alcohol, by floating alcohol on top of our DNA mixture, we can create an interface layer that will allow DNA to precipitate out. In addition, the reason why we prefer using cold alcohol instead of the warm one is because low temperatures can protect the DNA by slowing the enzymes activity down which could break it apart.

1. Firstly there are no differences between the DNA of plant cells and animal cells. The only difference between plant cells and animal cells is plant cells have cell walls that animal cells don’t. Both plant cells and animal cells are eukaryotic and have nuclear membrane where DNA is stored. Secondly, bacteria cells are prokaryotic and don’t have nucleus. Therefore, bacteria’s DNA is free floating in the cell.

1.   Firstly, as we have known, DNA is tightly bended into chromosomes. In addition, chromosomes are studied by using microscopes and the double helix of the unfolded chromosomes is so thin which cannot be detected by the microscope. Therefore, we cannot see the double helix of the DNA. Secondly, there is a molecule called histone, only found in eukaryotic organism, the DNA will wind and wrapped with histones, this will allow the DNA to be packaged into the neat nuclear structures called chromosomes which we can see through microscope.

1. In biological industry, scientists now can use the extracted DNA to create fingerprint to help analyse genetic diseases, solve criminal problems or even rebuild historical thing.

1. According to out result, our group have done the experiment quite good because we found the shape of the DNA. However, to have an improvement on this experiment, we could have calculated the volume of the fluid and alcohol more accurately to make the precipitate more clearly. In addition, we did wear lab coat and gloves in other to avoid being hit by any fluid or liquid and to make sure that our experiment run more safely.

Conclusion

       In conclusion, according to our result we have extracted and found the shape of the strawberry’s DNA through precipitation. In this experiment, lots of step are being used for DNA isolation, we used Soap Salty Fluid to dissolve phospholipid and separate DNA and protein, then next step we used alcohol to make the DNA precipitate. Besides, we now know that we cannot see the double helix of the DNA through microscope and we also know that the scientist can do lots of thing through DNA isolation.