Department of biology Essay

INTRODUCTION: Every cells of living organism contains genetic materials known as deoxyribonucleic acid, DNA. It can be isolated from tissue sample of living things by separating it from other cellular component in a manner that still preserves its structures. The structure of DNA is double-stranded helices that made up from the monomer of nucleotides. Each of the nucleotides composed of three parts that are the phosphate group, deoxyribose sugar backbone and also nitrogenous bases (Adenine, Guanine, Thymine and Cytosine). This nitrogenous base are arranged in sequence and holds the information and coding for controlling the physical trait that we all have as well as the regulation of our body. DNA extraction is simply a process that results in separation of DNA from the cells or viruses that are hosting it. Through the meaning is simple but the process is not. When we go into the peculiar details of DNA extraction, we realize that it’s more of an initial stage in other intensive DNA testing processes. DNA test could be performed for any reason; however for any DNA testing to happen the first stage normally is the isolation and extraction of DNA molecules from the cells that they reside in. DNA extraction follows a series of step, stripping all proteins from the DNA and the extraction protocols have to make sure that the DNA thus obtained via isolation and extraction is of high or acceptable quality. DNA isolation is a process of purification of DNA from sample using a combination of physical and chemical methods. Currently it is a routine procedure in molecular biology or forensic analysis. Primary structure consists of linear sequence of nucleotides that are linked together by phospodiester bonds. It is the linear sequence of nucleotides that make up the primary structure of DNA. Specific techniques must be chosen for isolation of DNA from some samples such as samples from microorganisms with thick cellular wall, for example yeast. Biological DNA represents the information which directs the functions of a living thing. A. Yeast DNA Extraction Materials : 1 packet of dry yeast, Sodium chloride, Meat tenderizer, Ice cold 95% ethanol, Sunlight detergent, distilled water, blender, graduate cylinders ( 10mL, 100mL and 500mL ), Beaker ( 250mL, 100mL ), glass stirring rod and wooden sticks, 15mL test tube, test tube rack, 1 ,l pipette and blue tips. Method: 1. 1 packet of dry yeast was mixed with 40ml of 50Â °C tap water. The yeast was stir to dissolve and the mixture was leave and covered for 20 minutes. 2. Salt/detergent solution was prepared by adding 40 ml detergent and 40g NaCl to 360ml distilled water. The solution was mixed till dissolved. 3. 5% meat tenderizer solutions were prepared by adding 5g of meat tenderizer to 80 ml of distilled water. The solution was top up to 100 ml with distilled water. *salt / detergent solution and meat tenderizer solution is prepared once for Part A, B and C. *alternatively, 5% meat tenderizer solution may be substitute with 100 ml of fresh papaya juice or pineapple juice. 4. 40 ml of yeast mixture and 40 ml of salt/detergent solutions was placed in a blender and was blended at high speed for 2 minutes. 5. The solution was pour into the beaker and 15ml of meat tenderizer solution was added. The solution was stir to mix. 6. The mixture was leave at room temperature for 5 minutes. 7. A cheese cloth was place over a filter funnel. The mixture was pour over the filter funnel and the clear supernatant was collected. 8. 3 ml of clear solutions was transfer into a 15ml tube. 9. The test tube was tilted to a 45 degree position. 3 ml of 95% ice cold ethanol was gently added to the side of the tube. 10. The test tube was leave undisturbed for 3-5 minutes. A layer will be formed in the tube. 11. DNA precipitate was formed at the interphase layer. A wooden stick was used to swirl the DNA out Result : Table A(i) : Yeast DNA Extraction B. Onion DNA Extraction Materials : Fresh onion, salt detergent solution, meat tenderizer solution, ice cold 95% ethanol, distilled water, blender, graduated cylinders (10 ml and 100 ml), glass stirring rod and wooden sticks, 15 ml test tube, test tube rack, 1 ml pipette and blue tips. Method : 1. The prepared salt/detergent solutions and meat tenderizer solution from part A was gathered. 2. 3 medium sized onions were cut into an inch cube and were placed in a blender. 3. 100 ml of salt/detergent solution was added in a blender. 4. The solution was blended at high speed for 2 minutes. 5. A cheese cloth was placed over filter funnel. The mixtures were poured over the filter funnel and the clear supernatant was collected. 6. The clear solution was transfer into a beaker and 30 ml of meat tenderizer solution was added. 7. The mixtures were leave at room temperature for 5 minutes. 8. 3 ml of clear solutions was transfer into a 15 ml tube. 9. The test tube was tilted to a 45 degree position. 3 ml of 95% ice cold ethanol was gently added to the side of the tube. 10. The test tube was leave undisturbed for 3-5 minutes. A layer will be formed in the tube. 11. DNA precipitate was formed at the interphase layer. A wooden stick was used to swirl the DNA out. Result : Table B(i) : Onion DNA Extraction C. Apple and Orange DNA extraction Materials : Fresh apple, fresh orange, salt detergent solution, meat tenderizer solution, ice cold 95% ethanol, distilled water, blender, graduated cylinder ( 10 ml and 100 ml ), glass stirring rod and wooden sticks, 15 ml test tube, test tube rack, 1 ml pipette and blue tips. Methods : 1. The prepared salt/detergent solutions and meat tenderizer solution from part A was gathered. 2. An apple / orange were cut into an inch cube and were placed in blender. 3. 100 ml salt/detergent solutions were added in a blender. 4. The solution was blended at high speed for 2 minutes. 5. A cheese cloth was placed over filter funnel. The mixtures were poured over the filter funnel and the clear supernatant was collected. 6. The clear solution was transfer into a beaker and 30 ml of meat tenderizer solution was added. 7. The mixtures were leave at room temperature for 5 minutes. 8. 3 ml of clear solutions was transfer into a 15 ml tube. 9. The test tube was tilted to a 45 degree position. 3 ml of 95% ice cold ethanol was gently added to the side of the tube. 10. The test tube was leave undisturbed for 3-5 minutes. A layer will be formed in the tube. 11. DNA precipitate was formed at the interphase layer. A wooden stick was used to swirl the DNA out. Result : Table C(i) : Orange DNA Extraction Table C (ii) : Apple DNA Extraction RESULT ALL OF EXPERIMENTS: Sample Extraction Amount Apple Success Large Onion Success Small Orange Success Small Yeast Success Small DISCUSSION: Based on our experiment discussion, we obtained that the difference amount of DNA extraction from yeast, onion, apple and orange is different. The amount of apple DNA extraction is larger than onion, orange and apple DNA extraction. Each step of the process will help in a certain way to extract DNA, until we are finally successful in the end. In the yeast, extraction, the ethanol will be able to separate the DNA and it will float between the less dense ethanol and the denser homogenizing mixture. In the onion DNA extraction, the chloroform and homogenizing medium will help break down the cell membranes and the ethanol like in the yeast DNA extraction. It will cause the DNA to separate and be suspended in the interface between the two solutions. It will be same to apple and orange DNA extraction. The precaution step on this experiments we tilt 45Â º to add the ethanol. This is because it will form a layer on top of the sample because the ethanol is less than water. So, it does will be on the top of layer. We also used 50ï‚ ° of hot water in yeast solution. Its will formed the best of result because hot water is the optimum temperature for yeast. We also obtained about perceptions step why only clear solution produced in these experiments. Its means the extraction was failed. CONCLUSION: REFERENCES: http://www.whatisdna.net/dna-extraction.html http://classic.sidwell.edu/us/science/vlb5/Labs/DNA_Extraction_Lab/dna_extraction_lab.html#predictions http://sciencehk.weebly.com/lab-reports.html ANSWER AND QUESTION: Answer all the questions. 1. Describe the functions of following: a. Applying blender to sample and salt/detergent solutions Strain the DNA mixture. b. Salt Salty water helps the DNA precipitate (solidify and appear) when alcohol is added. c. Detergent Detergents are used to break down cell walls and nuclear membranes to release the DNA. They work by chemically poking holes in the cell membranes or walls. Once holes are poked in the membranes, the membranes can be further distrupted mechanically, as with a blander. After that, it’s easier to get the contents of the cell out, including the DNA, d. Meat tenderizer solutions Meat tenderizer acts as an enzyme. The DNA in the nucleus of the cell is moulded, folded, and protected by proteins. The meat tenderizer cuts the proteins away from the DNA. e. 95% ice cold ethanol Having ice cold ethanol only increases the rate of precipitation of DNA and helps increase yield of DNA. It can either use room temp or ice cold ethanol for DNA precipitation. Think about precipitation of a super concentrated solution as you decrease the temperature. As the temperature decreases, the amount of precipitation increases. Overall temperature affects solubility. As temperature decreases the substance becomes more insoluble (in general. this does not apply to every molecule). So, ice cold EtOH allows for more DNA to interact together and allow for a more rapid and efficient precipitation of DNA. 2. Compare the reliability amount of DNA obtained from all the samples. The reliability amount of DNA obtained from apple is much larger compared to Reliability amount of DNA from onion, orange and apple. 3. Write out the principle involved in DNA extraction. – Break open cells by mashing the fruit. – Dissolve organelles and cell membranes with detergent. – Separate DNA from proteins with salt – Filter out the clumps with a coffee filter – DNA precipitates in cold alcohol and is spooled out.