DNA and RNA Extraction and Isolation

Question 1

these methods rely on biochemical properties of the cellular components to elicit the desired molecular separation and might exhibit preference or exclusivity in extracting DNA or Rna on its intrinsic characteristics

Answer 1

chemical methods

Question 2

chemical techniques

Answer 2

Osmotic shock
Enzymatic
digestion
Detergents
Alkali treatmentl

Question 3

principle of Osmotic shock

Answer 3

Osmotic rupture of membrane

Question 4

Enzymatic digestion

Answer 4

Digestion of cell wall

Question 5

Detergents

Answer 5

Solubilization of membranes

Question 6

Alkali treatment

Answer 6

Solubilization of membrane

Question 7

harsh modes of lysis

Answer 7

alkali treatment

Question 8

cheap chemical techniques

Answer 8

Osmotic shock
Alkali treatment

Question 9

Cheap at small scale; expensive at large scale

Answer 9

Enzymatic
digestion

Question 10

Moderate cost

Answer 10

Detergents

Question 11

most usual application of osmotic shock

Answer 11

Spheroplasts and Protoplasts

Question 12

Most usual application of Enzymatic
digestion

Answer 12

Gram-positive and Gram-negative bacteria

Question 13

Most usual use of Detergents

Answer 13

General use

Question 14

Most usual application of Alkali treatment

Answer 14

Plasmid DNA

Question 15

• used to extract DNA from bacteria

Answer 15

Cesium Chloride (CsCI) Gradient Centrifugation with Ethidium Bromide (EtBr)

Question 16

Cesium Chloride (CsCI) Gradient Centrifugation with Ethidium Bromide (EtBr) is based on the phenomenon of?

Answer 16

buoyant and specific density

Question 17

the separation of RNA from DNA and proteins after extraction with an acidic solution, which consists mainly of GuSCN, sodium acetate, phenol, and chloroform, followed by centrifugation.

Answer 17

Guanidium Thiocyanate Phenol Chloroform Extraction

Question 18

acidic solutions used in Guanidinium Thiocyanate-Phenol-Chloroform Extraction

Answer 18

GuSCN, sodium acetate, phenol, and chloroform,

Question 19

in Guanidinium Thiocyanate-Phenol-Chloroform Extraction, where can total RNA and DNA proteins be found

Answer 19

total rna - remains in the upper aqueous phase
DNA - remain either in the interphase or in the lower organic phase (acidic condition)

Question 20

total RNA is recovered through

Answer 20

precipitation by isopropanol and can be used for subsequent process.

Question 21

used in the field of forensics for DNA extraction from various sources, such as hair, blood stain cards, and buccal swabs

Answer 21

Chelex® Extraction

Question 22

dedicated to plasmid DNA isolation

Answer 22

Alkaline Extraction

Question 23

basic principle of Alkaline Extraction

Answer 23

selective alkaline denaturation of high molecular weight chromosomal DNA, while covalently bond circular plasmid DNA remains intact.

Question 24

alkaline extraction: chromosomal DNA after neutralization

Answer 24

renatures and makes an insoluble precipitate

Question 25

alkaline extraction: plasmid DNA

Answer 25

remains in the supernatant.

Question 26

involves harvesting the bacteria of interest from culture media and exposing them to alkaline solution (consisting basically of **SDS and NaOH**).

Answer 26

Alkaline Extraction

Question 27

**poly(A) RNA** hybridizes with an **oligo(dT)-cellulose** matrix, under what conditions

Answer 27

high salt conditions

Question 28

based on liquid and stationary phases, which selectively separate the target analyte from the solution based on specific hydrophobic, polar, andlor ionic pronerties of both solute and sorbent.

Answer 28

Solid-Phase Nucleic Acid Extraction

Question 30

What is the main use of CsCl gradient centrifugation with EtBr?

Answer 30

Extracting DNA from bacteria

Question 31

What is the purpose of guanidinium thiocyanate-phenol-chloroform extraction?

Answer 31

Separating RNA from DNA and proteins

Question 32

How is total RNA recovered after Guanidinium Thiocyanate-Phenol-Chloroform extraction?

Answer 32

Precipitation with isopropanol

Question 33

What is the main use of Chelex® extraction?

Answer 33

Forensic DNA extraction from hair, blood stains, and buccal swabs

Question 34

How does Chelex® extraction prevent DNA degradation?

Answer 34

By **chelating metal ions**, which prevents DNA breakdown at high temperatures and low ionic conditions

Question 35

What is alkaline extraction used for?

Answer 35

Plasmid DNA isolation

Question 36

What is the principle behind alkaline extraction?

Answer 36

Selective alkaline denaturation of chromosomal DNA, while plasmid DNA remains intact

Question 38

What are the key reagents in alkaline lysis solution?

Answer 38

SDS (Sodium Dodecyl Sulfate) and NaOH

Question 39

How is Poly(A)+ RNA isolated?

Answer 39

By hybridizing with an oligo(dT)-cellulose matrix under high-salt conditions

Question 40

What is the principle of solid-phase nucleic acid extraction?

Answer 40

Selectively separates nucleic acids using a **liquid** and **stationary phase** based on **hydrophobic**, **polar**, and **ionic properties**

Question 41

What are the different types of solid-phase extraction (SPE)?

Answer 41

• Normal/Regular SPE • Reverse SPE • Ion Exchange SPE

Question 42

What solid phases are commonly used?

Answer 42

• Silica Matrices • Glass Particles • Diatomaceous Earth • Magnetic Beads

Question 43

What material is commonly used in magnetic beads-based purification?

Answer 43

Anion exchange material or cellulose matrix