नमस्कार विद्यार्थी मित्रांनो Isolation of DNA from given sample हे प्रॅक्टिकल Experiments to be performed - PART A मधील आहे. याचाच अर्थ तुम्हाला हे प्रॅक्टिकल Exam मध्ये Examiner ला Performe करून दाखवायचे आहे. म्हणूनच प्रॅक्टिकल Exam च्या दृष्टीने हे Experiment अतिशय महत्त्वाचे आहे. या ब्लॉग मध्ये आपण Practical Book मधील या Experiment Number - 9 ची उत्तरे पाहणारं आहोत. ही उत्तरे काळजीपूर्वक वाचून आपल्या Practical Book मध्ये लिहा किंवा तुमच्या कॉलेजमधील संबंधित विषय शिक्षकांची मदत घ्या.
9. Isolation of DNA from Given Sample.
Aim :- To extract an isolate DNA from a fruit sample.
Requirements :- Fleshy berry fruits like bananas, Zizyphus, grapes, etc. can be used. Fleshy fruits of banana, liquids soap, distilled water, salt (NaCl), 1000 ml ice cold isopropyl alcohol i.e. IPA [Chill the alcohol (IPA) by placing the test tubes in a beaker containing ice cubes and some water], measuring spoons, glass stirring rod, test tubes, glass beakers, plastic cups, strainer or coffee filter, funnel, etc.
Principle :- All plants DNA extraction protocols, comprise of basic steps of disruption of cell wall, cell membrane and nuclear membrane to release the DNA into solution followed by precipitation of DNA and ensuring removal of the contaminating biomolecules.
Figure :-
Procedure :-
1. The cells in a fruit sample are separated by physical means such as grinding, to form mash or blend.
2. Put ½ cup of distilled water and one banana blend in it. Then pour the mixture into the beaker.
3. Mix 1 teaspoon of liquid soap with ¼ teaspoon of salt in a plastic zip lock bag or cup. Add 2 tablespoons of distilled water and stir gently until the soap and salt are dissolved.
4. Add 2 tablespoons of banana mash mixture to the cup containing salt and soap solution. Stir the mixture for 10-15 minutes by using a glass rod.
5. After 15-20 minutes filter the fruit mixture through a fine sieve or coffee filter.
6. Take a test tube of chilled alcohol (IPA). Add filtrate to it with the help of a dropper, very slowly.
7. Place the test-tube undisturbed for 5-6 minutes.
8. A layer of alcohol floating on the top of the fruit mixture is now clearly visible.
9. The white material becomes visible as a precipitate that marks the isolated DNA.
10. It can be spooled out with the help of hook or bent paperclip or glass rod. Slowly draw the DNA up out of the solution.
Observations :- DNA precipitates out into the alcohol layer. DNA has the appearance of white stringy mucus.
Questions
1. Where is DNA found in the cell?
Ans :- In a typical eukaryotic cell, DNA is found in the nucleus, mitochondria, and chloroplasts.
2. What is the role of detergent in isolation of DNA?
Ans :- During the extraction of DNA, the detergent removes the lipids from the cell membrane and nuclear membrane, allowing the DNA to be released from the cell.
3. Why salt is added to isolate DNA?
Ans :- During DNA isolation, salt is added to neutralize the DNA's charge and make the molecule less hydrophilic, meaning less soluble in water. The salt also helps remove proteins that are bound to the DNA.
4. Why is chilled condition required during the experiment?
Ans :- During DNA isolation, chilling is necessary to increase the rate of DNA precipitation and to protect the DNA from the activity of cytoplasmic DNases.
Multiple Choice Questions
1. Which of the functions is not performed by DNA?
a. Synthesis of protein
b. Transmission of hereditary character
c. Synthesis of carbohydrates
d. Replication
Ans :- c. Synthesis of carbohydrates
2. Purines of DNA or RNA are...
a. Uracil and guanine
b. Uracil and cytosine
c. Adenine and guanine
d. Cytosine and guanine
Ans :- c. Adenine and guanine
3. Make the correct statement:
a. Histones are acidic proteins
b. Histones stimulate genetic activity
c. Histones are basic proteins
d. Nucleosomes are formed in E.coil, during packaging
Ans :- c. Histones are basic proteins
4. Which of the following nucleotide sequences has 4 pyrimidine bases?
a. GCUAGACAA
b. UAGCGGUAA
c. GATCAATGC
d. GCAAGAUCAA
Ans :- c. GATCAATGC
5. A nucleoside is...
a. A pentose sugar ribose or deoxyribose + a nitrogen base
b. A nucleoside + phosphate
c. A pentose sugar + a phosphate
d. A pentose sugar ribulose + aN2 base
Ans :- a. A pentose sugar ribose or deoxyribose + a nitrogen base
*PDF Link - Click Me :) or Click on Download Button Below:
*Click on 'Next' to view next practical Answer or 'Previous' to previous one!
