week7: NUCLEIC ACID ISOLATION ANDTECHNIQUESINEXTRACTION Flashcards
a process of reducing a very pure nucleic acid, DNA and RNA, that is free from contaminants
extraction of nucleic acid
goal of extraction of nucleic acid
to produce a very pure nucleic acid to use in nucleic acid testing such as PCR, blotting nucleic acid, and gel electrophoresis
2 main methods used in extraction
precipitation and centrifugation1
1869 the first one who isolated nucleic acid
friedrich miescher
friedrich miescher
He discovered it when he was studying the chemical nature of the nuclei of the ___
white blood cell
a method that friedrich miescher used to extract nucleic acid
precipitation
the key discoverer of semi-conservative model of DNA
meselson and stahl
what methods do meselson and stahl used to discover the semi conservicative model of DNA
centrifugation - density
Nucleic acid extraction can be divided into three
steps:
breaking open tissues and cells
removing proteins/lipids/contaminants
transferring the nucleic acid to water or buffer solution that will preserve them without interfering with subsequent work
breaking open tissues and cells is also called as
cell lysis
mechanism to lyse a cell is
physical and chemical
example of chemical lysing agent
on our experiment, we use of detergent
what is the most commonly used
type of lysis buffer?
1-2% sodium dodecyl sulfate
a reagent that will help to remove the protein contaminants
proteinase K
a reagent that will help to remove the cell wall of gram negative bacteria
lysozymes
a process called as removing contaminants is
homogenization or purification
a reagent that will help to remove the peptidoglycan of gram positive bacteria
aminopeptidase
the substep under the purification of nucleic acid
precipitation using alcohol
why alcohol is used in precipitation of nucleic acid
insoluble in alcohol
the purpose of the last step of nucleic acid extraction
for solubilization of the nucleic acid
what is the media used in solubilization of the nucleic acid / resuspension
eluting buffer
- tris HCL
- tris acetate EDTA buffer
- molecular grade water
the last step of extracting DNA is called is
elution
the product of elution is called as
eluate
CONSIDERATIONS FOR CHOOSING ISOLATION
METHOD
- specimen type - cellularity
- amount of sample and desired yield
- purity and size of isolate
- ease of operation and throughout
- cost and hazards
the DNA extracted from organism is called as
plasmid
3 main types of nucleic acid isolation
solid phase isolation
liquid phase isolation
chelex 100 method
the easiest method of isolation
solid phase
the most expensive method of isolation
chelex 100
the cheapest method of isolation
liquid phase isolation
liquid phase isolation uses phenol and chloroform. What are its downside
phenol can cause burns and chloroform is carcinogenic
this isolation method is cheap but has low yield of nucleic acid
liquid phase isolation
SAMPLES FOR MOLECULAR DIAGNOSTIC
the bacteria used for extraction is what gram type of bacteria
gram negative bacteria
SAMPLES FOR MOLECULAR DIAGNOSTIC
the fungi used for extraction is extracted in what part
yeast form and in hyphal structure
SAMPLES FOR MOLECULAR DIAGNOSTIC
the virus used for extraction is contaminated by ___
the dna of the host since they disintegrate themselves on the host cell
SAMPLES FOR MOLECULAR DIAGNOSTIC
the virus used for extraction is performed by this method ___
centrifugation
SAMPLES FOR MOLECULAR DIAGNOSTIC
the worms used for extraction is ___ prior to extraction
teased, grinded, minced
SAMPLES FOR MOLECULAR DIAGNOSTIC
the bacteria used for extraction is collected in what phase ___
harvested that grows in less than 24 hrs incubated
in mid logarithmic phase which means it’s activately dividing and growing
SAMPLES FOR MOLECULAR DIAGNOSTIC
the blood used for extraction is ___
the one that is collected in tripotassium EDTA (EDTA K3) and acid-citrate-dextrose
purple and yellow top
SAMPLES FOR MOLECULAR DIAGNOSTIC
the forensic science we need for extraction is ___
chain of custody
why heparin is not used for extraction if using blood as sample
2 reason
- coextracted in the DNA extraction
- it inhibits enzymes such as reverse transcriptase and taq polymerase
SAMPLES FOR MOLECULAR DIAGNOSTIC
the tissue for extraction is ___
fresh and reserve
SAMPLES FOR MOLECULAR DIAGNOSTIC
the human cell used for extraction is ___
hair shaft, cells in nasopharyngeal and oropharyngeal
SAMPLES FOR MOLECULAR DIAGNOSTIC
the stool sample used for extraction is ___ prior extraction
digestion and decontamination
SAMPLES FOR MOLECULAR DIAGNOSTIC
the sediments used for extraction is ___ prior the extraction
centrifuge
SAMPLES FOR MOLECULAR DIAGNOSTIC
the plant used for extraction is extracted in what area
root and stem
MOSTCOMMONLYUSEDDNAEXTRACTION
PROCEDURES
liquid, solid, chelex 100
LIQUID PHASE ISOLATION METHOD
what are its 2 types
organic and inorganic
organic extraction of liquid-phase isolation method is through
phenol and chloroform which can cause burns and carcinogenic
inorganic extraction of liquid-phase isolation method is through the use of
proteinase K and salting out
salting out has what concentration of acid and salt
low pH and high salt concentratrion
Solid PHASE ISOLATION METHOD
what are its 2 types
manual method (silica-based method)
automated method (magnetic beads isolation)
the first type of solid phase extraction that is known as silica-based method uses specialized column with silica is called as
spin column
the two type of solid phase isolation (silica based and magnetic beads) follows the same process which are
adsorption and elution
the process which the solid phase method follows and is about binding and washing of nucleic acid
adsorption
the process which the solid phase method follows and is about transferring of nucleic acid for resuspension
elution
most preferred method and most commonly used isolation method
solid phase isolation