3: DNA and RNA Extraction (PRELIMS) lec based Flashcards
a procedure used to isolate DNA from the nucleus of cells from other cellular components
DNA Extraction
two main methods of cell lysis in DNA purification
physical and chemical methods
What is the purpose of DNA extraction
to obtain DNA in a relatively purified from that can be used for further investigations
T or F
DNA can only be isolated from a living organism
F (living or dead organism)
use this card to familiarize yourself with sources of DNA
whole blood
hair
sperm
bones
nails
tissues
saliva
buccal swabs
epithelial cells
urine
use this card to familiarize your self with the steps in DNA extraction (or enumerate it if ur a masochist)
- preparation of a cell extract
- purification of DNA from a cell extract
- concentration of DNA samples
- Measurement of purity of the DNA concentration
What is the other term for cell extract preparation
cell lysis
what does EDTA remove to compromise the stability of the cell membrane?
Calcium and Mg ions
what is the main purpose of cell lysis
liberate / expose the DNA
what does the SDS (sodium dodecyl sulfate) remove to disrupt the cell membrane
lipids of the cell membrane
What method is used to extract DNA from a whole blood sample
Ficoll-directed gradient through centrifugation
Proteinase K
Phenol
what reagent is used in Ficoll-directed gradient through centrifugation
Ficoll-paque reagent
T or F
In using the Ficoll-Paque reagent, DNA is found at the top most layer after centrifugation
F (at the bottom)
Whole blood
what is proteinase K mixed with for an enzymatic method of DNA extraction
whole blood + Tris EDTA + SDS + MgCl
what is phenol mixed with for DNA extraction in whole blood
whole blood + Tris HCl + phenol + Mg
process for 4 hours
centrifuge
wala na ata mg here (edit)
At what room temperature are Dry blood spots stored at?
room temp or -20 degrees Celsius for prolonged storage
what are the two reagents used to extract DNA from dry blood spots
Chelex-100 and Insta Gene Matrix
at what temperature is the sample with chelex reagent left to incubate in?
100 degrees (boiling)
at what temperature is the sample with InstaGene Matrix left to incubate in ?
56 degrees celsius
how long is the sample with chelex left to incubate
8 mins
how long is the sample with instagene left to incubate
30 mins
Where is the DNA found in both chelex and instagene methods after centrifugation
DNA will be found at the supernatant
what are the two methods of extracting DNA from hair
alkaline lysis method and digestion
For alkaline Lysis Method:
how long is the sample incubating for and at what temperature
95 degrees Celsius for 10 mins
For Alkaline Lysis Method:
what buffer is used
NaOH buffer
What is the reagent used for the digestion method in extracting DNA from hair
dithiothreitol
Digestion method (DNA extraction from hair)
How long is the sample incubating for and at what temperature
2 hours at 56 degrees celsius
What is the buffer used in DNA extraction for saliva
lysis buffer
lysisbuffer: tris EDTA, SDS, Proteinase K
In DNA extraction from saliva
How long is the sample incubating for and at what temperature
1-3 hours at 56 degrees celsius
What is the reagent used in DNA extraction from urine
lysis buffer
DNA extraction from urine:
what is the first step
centrifugation
DNA extraction from urine:
What do you discard in the second step (after centrifugation)
supernatant
DNA extraction from urine:
how long do you incubate the sample and at what temperature
15 mins at -20 degrees celsius
DNA extraction from urine:
last step
add lysis buffer
T or F
bacteria and fungi ‘s cell walls must be broken to release the nucleic acid
T
DNA extraction for microorganisms
What are the reagents used in the chemical method
Detergents
Cetyltrimethylammonium bromide (CTAB)
DNA extraction for microorganisms
What are the enzymes that may be used
Lysozyme and Lyticase
What are the two methods of DNA extraction for Formalin-Fixed, Paraffin-embedded tissue
deparaffinization
Glycine in alkaline environment
What is the first step in deparaffinization
de-waxing
use this card to familiarize yourself with the steps in deparaffinization
- De-waxing
- heating
- Application of organic solvents, Microwaving, heating with mineral oil
- Digestion using proteinase K
- purification