Kapunan - Activity 06.pptx Cell and Molecular | DNA Extraction

This presentation tackles on DNA Extraction.

1. 01 Activity 06 | DNA EXTRACTION Kapunan, F.A.C. | BS BIO 3C

2. Q1. Give at least three purposes, why there is a need to isolate DNA. a. Genetic testing b. Body identification c. Analysis of forensic evidence 02 Q2. Why DNA extraction is important in the process of isolating DNA? DNA extraction is crucial to posses the cells with the DNA that makes the DNA extract. The DNA is purified first to separate proteins and other cellular contaminants and leaves the DNA extract. . Q3. Why DNA purification is needed? Purification of DNA is important as it filters the cellular debris from the DNA. These contaminants lessen the shelf life of the final outcome of purified DNA and will cause errors to possible research studies.

3. Q4. Where is DNA located within a cell? How much DNA is found there? The DNA is located within the cell secured inside a cell’s nucleus. Inside the nucleus is approximately 2 meters of DNA. Q5. Explain the step-by-step processes of DNA extraction. Lysis – the 1st step of DNA extraction where the cell membrane and nuclear membrane are burst open using detergents and proteinase K. The isolated cheek cell sample are placed in a warm bath deactivate enzymatic activities. Precipitation – the 2nd step of DNA extraction is the addition of concentrated solution to precipitate the proteins and cellular debris. It is then centrifuged to completely separate the debris from DNA. The liquid with DNA is transferred to another tube. DNA Purification – the 3rd step of DNA extraction is purified using isopropyl alcohol. The alcohol causes the DNA to clump together and precipitate to a visible form. It is then centrifuged to settle the DNA at the bottom of the tube, and stored at an appropriate temperature.

4. Q6. What cells are used in DNA extraction? The cells used for the DNA extraction are cheek cells. The cheek cells inside the lining of the mouth loses uncountable cells, which is why cheek cells are used. 02 Q7.Explain the four steps used in the purification of DNA. a. Collect cheek cells from the test subject to gather DNA b. Burst cells open to release DNA c. Separate DNA from proteins and debris d. Isolate concentrated DNA Q8. What does the term “Lysis” mean? What is the purpose of this solution? Lysis is a Greek word that means “to separate”. Hence, the lysis solution separates the DNA from cells by inducing the cell to burst open, and release the DNA.

5. Q9. What are the two chemicals present in the lysis solution? The chemicals used to form the lysis solution is detergent, and proteinase K. 02 Q10. What does the detergent do to the cell? What does the proteinase K do? Detergent consists of anionic and/or cationic properties that causes it to be denaturing or non-denaturing while adhering to the protein structure. The properties of detergent disrupt the hydrophobic and hydrophilic systems of the membranes. This then causes the membrane proteins and lipids to solubilize causing the cell membrane structure to lyse as well as the nuclear membrane. Once the membranes have burst open, the proteinase K cuts the histones proteins by inactivating the DNases or RNases which is an enzyme that catalyzes the hydrolytic cleavage of phosphodiester bonds in the DNA or RNA backbone. This frees the DNA from the coiling to histone proteins.

6. Q11. What is the purpose of the warm water bath in DNA extraction? The warm water bath particularly between 55 degree and 60 degrees Celsius will deactivate the enzymes which aids to break down the cell membrane and free the DNA. 02 Q12. What is the purpose of salt solution? Since the detergent causes the proteins to solubilize, the salt solution then coagulates the proteins and debris after the DNA is separated.

7. Q13. What does the centrifuge do in the process? Why does it need to be balanced? The centrifuge is used to separate and settle the cellular debris from the DNA. Since it spins at a high speed, the precipitate of cellular debris and proteins are settled at the bottom of the tube. In order to achieve a result of proper separation of the heterogenous mixture, the centrifuge must be kept balance. Once the centrifuge is unbalanced, this cannot operate efficiently and will produce false results. 02 Q14. After being put into the centrifuge, in what layer is the DNA located? Once the centrifugation is finished, the cellular debris and proteins are observed at the bottom of the tube while the DNA remains floating freely in the liquid.

8. Q15. Why is the liquid containing the DNA added to isopropyl alcohol? Isopropyl alcohol causes the DNA to precipitate into a white visible form because the DNA clumps together and settles. This is because, DNA becomes less soluble in solutions containing isopropyl. 02 Q16. Why does the DNA sink to the bottom of the tube after it is centrifuged? Since the DNA have become less soluble and is coagulated together, the heavy form of precipitated DNA naturally settles to the bottom of the tube after centrifugation.

9. 01 Activity 06 | DNA EXTRACTION Kapunan, F.A.C. | BS BIO 3C THANK YOU.