DNA extractions (lab)

Question 1

DNA stands for?

Answer 1

D: Deoxyribose
N: Nucleic
A: Acid

Question 2

what is DNA extraction?

Answer 2

is the isolation and purification of DNA (deoxyribonucleic acid)

Question 3

DNA extraction principles?

Answer 3

• Break down cell membrane.

- Stabilization of the delivered DNA
-precipitation of the DNA with an alcohol

Question 4

you Break down cell membrane by?

Answer 4

• Detregent

- Heat : at (50-60) wich soften the phospholipid in the cell and nuclear membrane

Question 5

this to avoid the breakdown of DNA by

stabilizing its double bond strands frm , this done by?

Answer 5

1- concentrated NaCl : to keep the double bond stranded DNA and preciptate the protein particales around it .
2- EDTA : to inhibit the action of DNA enzyme

Question 6

As DNA is insoluble in alcohol , so it will
aggregate together to allow us to see it in the form of cotton like threads on the interface between the solution and alchol

Answer 6

…

Question 7

a technique that takes a
specific sequence of DNA of small
amounts and amplifies it to be
used for further testing is called?

Answer 7

PCR

Question 8

requirements for PCR

Answer 8

1) Template DNA (a sample of the DNA that you wish to replicate (Enzyme that replicates DNA)The most commonly used is the Taq DNA polymerase

2) Two Primers (forward and reverse)
• Are starting/ending points for DNA replication;
•Define the region of DNA to be replicated in PCR)

3) DNA polymerase

4) dNTPs (DeoxyribonucleosideTriphosphates
(dATP, dCTP, dGTP, dTTP)

5) Buffer (helps to stabilize the pH ) contains MgCL that activates the DNA polymerase

Question 9

what is a primer for each target sequence on the end of your DNA is needed?

Answer 9

allows both strands to be copied simultaneously in both directions

Question 10

what does Taq stand for?

Answer 10

Thermus aquaticus (a microbe found in 176°F hot springs)

Question 11

Taq produces an enzyme called?

Answer 11

DNA polymerase

Question 12

PCR (polymerase chain reaction) steps?

Answer 12

1) Denaturation: DNA strands are separated by heating to 95 C

2) Annealing: process of allowing two
sequences of DNA to form hydrogen bonds. annealing of the target sequences and
primers is done by cooling the DNA to 55 C

3) Extension: This step is performed by the taq polymerase enzyme. New complementary DNA strands are synthesized by adding dNTPs. The extension starts from the 3’ end of the complementary primers. The optimum temperature for this step is 72°C

Question 13

A programmable device that
cycles between specific temperatures
for set periods of time is the?

Answer 13

Thermal Cycler

Question 14

The cycling reactions temperatures?

Answer 14

Denaturation at 94oC
Annealing at 54oC
Extension at 72oC

Question 15

The products of PCR reactions

are analyzed by…………… in agarose gels , followed by ……………… and visualization with U.V.

Answer 15

separation, ethidium bromide staining

Question 16

PCR (polymerase chain reaction) applications are?

Answer 16

• DNA isolation (cloning)
• Disease detection (study of mutations)
• DNA sequencing
• Pathogens detection
• Forensic

Question 17

The products of PCR reactions are analyzed by separation in agarose gels , followed by ethidium bromide staining
and visualization with U.V

Answer 17

…