DNA Isolation

DNA ISOLATION
INTRODUCTION:
Deoxyribonucleic acid (DNA) isolation is an extraction process of DNA from various sources. Methods used to isolate DNA are dependent on the source, age, and size of the sample. Despite the wide variety of methods used, there are some similarities among them. In general, they aim to separate DNA present in the nucleus of the cell from other cellular components.
Isolation of DNA is needed for genetic analysis, which is used for scientific, medical, or forensic purposes. Scientists use DNA in a number of applications, such as introduction of DNA into cells and animals or plants, or for diagnostic purposes. In medicine the latter application is the most common. On the other hand, forensic science needs to recover DNA …show more content…
This is accomplished by adding salt and ethanol to a solution containing DNA or RNA. In the presence of salt (in particular, monovalent cations such as sodium ions (Na+)), ethanol efficiently precipitates nucleic acids. The purified precipitate can be collected by centrifugation, and then suspended in a volume of choice.

PROTOCOL:
CTAB method for DNA extraction protocol
 Take 2ml broth in a micro centrifuge tube
 Centrifuge @14,000 rpm for 15 minutes
 Discard the supernatant and collect the pellet
 Dissolve the solution in GTE solution
 First vortex it and then centrifuge @8000rpm for 15 minutes
 Collect the pellet and add 450 µl of GTE solution plus add 50µl Lysosymes (freshly prepared)
 Incubate it and keep it overnight at 37 degrees
 Add 10% of 200 µl SDS and mix gently
 Add 50µl of ProteinaseK
 Incubate at 55 degrees for one hour
 Add 200µl of 5M NaCl
 Add 160µl CTAB (it is viscous at room temperature therefore already pre heated)
 Incubate at 65degrees for 30 minutes
 Add chilled chloroform and shake vigorously
 Centrifuge @8000rpm for 15 minutes at 4 degrees
 Take only the aqueous phase in a new centrifuge tube and shake