DNA Isolation

DNA isolation is a process of purification of DNA from using a combination of physical and chemical methods. The first isolation of DNA was done in 1869 by Friedrich Miescher.
Isolation of DNA basically consists of four major steps.
i. Preparation of a cell extract.
ii. Purification of DNA from cell extract.
iii. Concentration of DNA samples.
iv. Measurement of purity of DNA concentration.
Reagents used for
A. Preparation of cell extract
1. Ethylene Diamine Tetra Acetate (EDTA) removes Mg2+ ions.
2. Sodium Dodecyl Sulfate (SDS) disrupts the cell membranes
3. Centrifugation

B. Purification of DNA .
1. Ethanol precipitation.
2. Phenol—chloroform extraction.
3. Mini column purification.

Removal of Protein impurities

C. Concentration of DNA

D. Measurement of purity of DNA Concentration
Absorbance is measured at 260 nm by UV absorbance spectrometer.
i.1.0 corresponds to 50 µg of ds DNA per ml.
ii.A260 nm and 280 nm ratio equal to 1.8, Pure DNA sample
ii.Ratio less than 1.8, contaminated, either with protein or with phenol.

Application of DNA Isolation
1.Diagnosis :
Mutation that is DNA sequence change
Genetic polymorphism
2.Forensic medicine:
For paternity testing and
Identification of individuals.
3.Medicine:
To identify specific source of virulence of organisms in community or hospital
4.Constructing genome libraries
5. for RT-PCR eg Corona Virus is an RNA virus whose RNA is separated from Oro and Nasopharyngeal swab samples and then reverse transcribed to DNA and then amplified by PCR

[swarnalisarkar]

I don't know what to say. Ma'am this video is so helpful and incredible, I quickly became a fan of yours. Thank you so so much for this.

[senarapremawansha]

THANK you so much... its very clear explanation.... may your knowledge be further enhanced ..

[architverma]

मैडम जी, आपको शत शत नमन मे बहुत दिनों से इंटरनेट पर इस टॉपिक को देख रहा था लकीं अच्छे से कोई भी नहीं समझ रहा था। हमारे कॉलेज के प्रोफेसर आप जैसे होजाये तो हमे किसी और की जरूरत ही ना पड़े।

[yalnaz]

Thank you for explaining in such an easy way, found very much helpful .

[theaf]

well explained with every aspect covered

[shubhamsinghrajput]

Thank You So Much Mam, You Explained Very Well.😊👍

[geetanjalirajput]

thanks for this explaination this is very understading and simple video for practicle knowladge

[ishitvabarway]

Mam can you please explain how to isolate dna from plant cell as it contains cell wall over cell membrane, how could we dissolve/ degrade it?

[komalpreetkaur]

Mam please add explanation, why we are adding so and so chemicals, u are just reading the ppt

[AlokSingh-vkoc]

Maam I need you ppt to present seminar plzz provide me...

[arinaaba]

Mam isolation of DNA from blood by organic and inorganic method and isolation of DNA from e coli plz explain kr dn thanks

[syed-wdib]

after how many years, we can't isolate DNA from a blood and hair sample.

[vivekgupta-ilnu]

Useless Presentation.No practical demonstration.nothing to ignite interest.