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In DNA extraction, what is the purpose of NaOH?
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+ Dna
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+ Sodium hydroxide
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Lostinspace1205
In DNA extraction, what is the purpose of NaOH?
It isn’t. I did a fair bit of this back in the day, and at no point was garlic employed in any way whatsoever, not even hung above the fridge where we kept blood samples to ward off vampires who fancied an ice lolly.
It isn’t. I did a fair bit of this back in the day, and at no point was garlic employed in any way whatsoever, not even hung above the fridge where we kept blood samples to ward off vampires who fancied an ice lolly.
NaOH ( Sodium hydroxide) is used as alkaline lysis buffer. It helps in dissolving the cell membrane so that the inner components of the cell including the DNA come out.
NaOH ( Sodium hydroxide) is used as alkaline lysis buffer. It helps in dissolving the cell membrane so that the inner components of the cell including the DNA come out.
EDTA is responsible for chelation of divalent ions. It stops the action of DNases found in cytoplasm of cells.
For DNA extraction, cells and nucleus need to be disrupted. Therefore, DNA comes in contact with DNases present in the cytoplasm. These DNases, DNA cutting enzymes, can destroy the genomic DNA and reduce the yield of gDNA considerably. Mg2+ is an important factor for activity of DNases. EDTA deprives the enzyme of this co-factor and renders it inactive.
EDTA is responsible for chelation of divalent ions. It stops the action of DNases found in cytoplasm of cells.
For DNA extraction, cells and nucleus need to be disrupted. Therefore, DNA comes in contact with DNases present in the cytoplasm. These DNases, DNA cutting enzymes, can destroy the genomic DNA and reduce the yield of gDNA considerably. Mg2+ is an important factor for activity of DNases. EDTA deprives the enzyme of this co-factor and renders it inactive.
In DNA isolation or extraction, NaOH ( Sodium hydroxide) is used as alkaline lysis buffer. It basically helps in dissolving the cell membrane so that the inner components of the cell including the DNA come out. The dissolution process happens when NaOH along with SDS (Sodium Dodecyl Sulphate) breaks the hydrogen bonding (H bonds) between the two strands of the double stranded DNA helix and denatures them into a single strand. This method is called the Alkaline Lysis method.
In DNA isolation or extraction, NaOH ( Sodium hydroxide) is used as alkaline lysis buffer. It basically helps in dissolving the cell membrane so that the inner components of the cell including the DNA come out. The dissolution process happens when NaOH along with SDS (Sodium Dodecyl Sulphate) breaks the hydrogen bonding (H bonds) between the two strands of the double stranded DNA helix and denatures them into a single strand. This method is called the Alkaline Lysis method.
To precipitate DNA, some amount of SALT along with ETHANOL is added.
Ethanol plays an important role being the solvent in precipitation of DNA.
NOW ANSWER TO HOW DOES IT HAPPEN?
SOLUBILITY : DNA (or RNA or any nuleic acid) is a polar molecule.
{Why polar?? Because of the phosphate group. Phosphate is negatively charged, which is why DNA macromolecules are predominately negative.}
Being polar, DNA is hydrophilic molecule, thus it dissolves well in water. (principle of ‘like dissolves like’)
Ethanol has both polar and non-polar parts. C2H5 is non-polar and -OH part is polar.
And thus, ethanol can dissolve both polar (hydrophilic) and non-polar (hydrophobic) molecules. WAIT WHAT!?? SO WHY DOESN'T IT DISSOLVE DNA??
IT DOES DISSOLVE DNA.. YES IT DOES!! but our books say that ethanol precipitates the DNA..
The catch is.. The salt (which is added along with ethanol) is responsible for precipitation.
both water and ethanolz are great solvents. And DNA dissociates into positive part and negative (PO3-) part when dissolved in any of them.
The salt: the role here is to neutralize the charge on phosphate group of DNA.
salts like Sodium chloride or sodium acetate can be used.
Salt, when dissolved in a solvent, dissociate into positive (Na) part and negative (Cl or acetate) part.
The dissociated positive part of the salt (Na+) NEUTRALIZES the dissociated negative part of the DNA (PO3-) which now makes the DNA far less hydrophilic which leads to precipitation even in polar solvents.
Role of ETHANOL: for dissociation of salt and DNA, best solvent considered is ethanol. Question is why ethanol? Why not water?
Aswer to this can be given on the basis of the “COULOMB‘s LAW of electrostatic forces”.
PO3- (anions) from the DNA are electrostatically attracted by the Sodium ions from the salt. According to coulomb’s law, force of attraction between any two opposite charges is INVERSELY proportional to the Dielectric constant.
i.e.
Less is the dielectric constant of the solvent, more will be the force of attraction between PO3- (from DNA) and Na+(from salt added)
And thus more effective will be the lowering in polar nature of DNA and less will be the solubility of DNA in polar solvent
And thus more will be the precipitation of DNA.
And the fact says:
Dielectric constant of water: 80
Dielectric constant of ethanol: 24.3
Thus, a polar solvent with less dielectric constant is used for precipitation of DNA. i.e. Ethanol.!!
To precipitate DNA, some amount of SALT along with ETHANOL is added.
Ethanol plays an important role being the solvent in precipitation of DNA.
NOW ANSWER TO HOW DOES IT HAPPEN?
SOLUBILITY : DNA (or RNA or any nuleic acid) is a polar molecule.
{Why polar?? Because of the phosphate group. Phosphate is negatively charged, which is why DNA macromolecules are predominately negative.}
Being polar, DNA is hydrophilic molecule, thus it dissolves well in water. (principle of ‘like dissolves like’)
Ethanol has both polar and non-polar parts. C2H5 is non-polar and -OH part is polar.
And thus, ethanol can dissolve both polar (hydrophilic) and non-polar (hydrophobic) molecules. WAIT WHAT!?? SO WHY DOESN'T IT DISSOLVE DNA??
IT DOES DISSOLVE DNA.. YES IT DOES!! but our books say that ethanol precipitates the DNA..
The catch is.. The salt (which is added along with ethanol) is responsible for precipitation.
both water and ethanolz are great solvents. And DNA dissociates into positive part and negative (PO3-) part when dissolved in any of them.
The salt: the role here is to neutralize the charge on phosphate group of DNA.
salts like Sodium chloride or sodium acetate can be used.
Salt, when dissolved in a solvent, dissociate into positive (Na) part and negative (Cl or acetate) part.
The dissociated positive part of the salt (Na+) NEUTRALIZES the dissociated negative part of the DNA (PO3-) which now makes the DNA far less hydrophilic which leads to precipitation even in polar solvents.
Role of ETHANOL: for dissociation of salt and DNA, best solvent considered is ethanol. Question is why ethanol? Why not water?
Aswer to this can be given on the basis of the “COULOMB‘s LAW of electrostatic forces”.
PO3- (anions) from the DNA are electrostatically attracted by the Sodium ions from the salt. According to coulomb’s law, force of attraction between any two opposite charges is INVERSELY proportional to the Dielectric constant.
i.e.
Less is the dielectric constant of the solvent, more will be the force of attraction between PO3- (from DNA) and Na+(from salt added)
And thus more effective will be the lowering in polar nature of DNA and less will be the solubility of DNA in polar solvent
And thus more will be the precipitation of DNA.
And the fact says:
Dielectric constant of water: 80
Dielectric constant of ethanol: 24.3
Thus, a polar solvent with less dielectric constant is used for precipitation of DNA. i.e. Ethanol.!!
It isn’t. I did a fair bit of this back in the day, and at no point was garlic employed in any way whatsoever, not even hung above the fridge where we kept blood samples to ward off vampires who fancied an ice lolly.
It isn’t. I did a fair bit of this back in the day, and at no point was garlic employed in any way whatsoever, not even hung above the fridge where we kept blood samples to ward off vampires who fancied an ice lolly.
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NaOH ( Sodium hydroxide) is used as alkaline lysis buffer. It helps in dissolving the cell membrane so that the inner components of the cell including the DNA come out.
NaOH ( Sodium hydroxide) is used as alkaline lysis buffer. It helps in dissolving the cell membrane so that the inner components of the cell including the DNA come out.
More
VOTE
EDTA is responsible for chelation of divalent ions. It stops the action of DNases found in cytoplasm of cells.
For DNA extraction, cells and nucleus need to be disrupted. Therefore, DNA comes in contact with DNases present in the cytoplasm. These DNases, DNA cutting enzymes, can destroy the genomic DNA and reduce the yield of gDNA considerably. Mg2+ is an important factor for activity of DNases. EDTA deprives the enzyme of this co-factor and renders it inactive.
EDTA is responsible for chelation of divalent ions. It stops the action of DNases found in cytoplasm of cells.
For DNA extraction, cells and nucleus need to be disrupted. Therefore, DNA comes in contact with DNases present in the cytoplasm. These DNases, DNA cutting enzymes, can destroy the genomic DNA and reduce the yield of gDNA considerably. Mg2+ is an important factor for activity of DNases. EDTA deprives the enzyme of this co-factor and renders it inactive.
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VOTE
In DNA isolation or extraction, NaOH ( Sodium hydroxide) is used as alkaline lysis buffer. It basically helps in dissolving the cell membrane so that the inner components of the cell including the DNA come out. The dissolution process happens when NaOH along with SDS (Sodium Dodecyl Sulphate) breaks the hydrogen bonding (H bonds) between the two strands of the double stranded DNA helix and denatures them into a single strand. This method is called the Alkaline Lysis method.
Hope this answers your question.
Cheers :)
In DNA isolation or extraction, NaOH ( Sodium hydroxide) is used as alkaline lysis buffer. It basically helps in dissolving the cell membrane so that the inner components of the cell including the DNA come out. The dissolution process happens when NaOH along with SDS (Sodium Dodecyl Sulphate) breaks the hydrogen bonding (H bonds) between the two strands of the double stranded DNA helix and denatures them into a single strand. This method is called the Alkaline Lysis method.
Hope this answers your question.
Cheers :)
More
VOTE
It's not just ethanol which precipitates DNA.
To precipitate DNA, some amount of SALT along with ETHANOL is added.
Ethanol plays an important role being the solvent in precipitation of DNA.
NOW ANSWER TO HOW DOES IT HAPPEN?
{Why polar?? Because of the phosphate group. Phosphate is negatively charged, which is why DNA macromolecules are predominately negative.}
Being polar, DNA is hydrophilic molecule, thus it dissolves well in water. (principle of ‘like dissolves like’)
Ethanol has both polar and non-polar parts. C2H5 is non-polar and -OH part is polar.
And thus, ethanol can dissolve both polar (hydrophilic) and non-polar (hydrophobic) molecules. WAIT WHAT!?? SO WHY DOESN'T IT DISSOLVE DNA??
IT DOES DISSOLVE DNA.. YES IT DOES!! but our books say that ethanol precipitates the DNA..
The catch is.. The salt (which is added along with ethanol) is responsible for precipitation.
both water and ethanolz are great solvents. And DNA dissociates into positive part and negative (PO3-) part when dissolved in any of them.
salts like Sodium chloride or sodium acetate can be used.
Salt, when dissolved in a solvent, dissociate into positive (Na) part and negative (Cl or acetate) part.
The dissociated positive part of the salt (Na+) NEUTRALIZES the dissociated negative part of the DNA (PO3-) which now makes the DNA far less hydrophilic which leads to precipitation even in polar solvents.
PO3- (anions) from the DNA are electrostatically attracted by the Sodium ions from the salt. According to coulomb’s law, force of attraction between any two opposite charges is INVERSELY proportional to the Dielectric constant.
i.e.
And the fact says:
Dielectric constant of water: 80
Dielectric constant of ethanol: 24.3
Thus, a polar solvent with less dielectric constant is used for precipitation of DNA. i.e. Ethanol.!!
Hope it helped :)
It's not just ethanol which precipitates DNA.
To precipitate DNA, some amount of SALT along with ETHANOL is added.
Ethanol plays an important role being the solvent in precipitation of DNA.
NOW ANSWER TO HOW DOES IT HAPPEN?
{Why polar?? Because of the phosphate group. Phosphate is negatively charged, which is why DNA macromolecules are predominately negative.}
Being polar, DNA is hydrophilic molecule, thus it dissolves well in water. (principle of ‘like dissolves like’)
Ethanol has both polar and non-polar parts. C2H5 is non-polar and -OH part is polar.
And thus, ethanol can dissolve both polar (hydrophilic) and non-polar (hydrophobic) molecules. WAIT WHAT!?? SO WHY DOESN'T IT DISSOLVE DNA??
IT DOES DISSOLVE DNA.. YES IT DOES!! but our books say that ethanol precipitates the DNA..
The catch is.. The salt (which is added along with ethanol) is responsible for precipitation.
both water and ethanolz are great solvents. And DNA dissociates into positive part and negative (PO3-) part when dissolved in any of them.
salts like Sodium chloride or sodium acetate can be used.
Salt, when dissolved in a solvent, dissociate into positive (Na) part and negative (Cl or acetate) part.
The dissociated positive part of the salt (Na+) NEUTRALIZES the dissociated negative part of the DNA (PO3-) which now makes the DNA far less hydrophilic which leads to precipitation even in polar solvents.
PO3- (anions) from the DNA are electrostatically attracted by the Sodium ions from the salt. According to coulomb’s law, force of attraction between any two opposite charges is INVERSELY proportional to the Dielectric constant.
i.e.
And the fact says:
Dielectric constant of water: 80
Dielectric constant of ethanol: 24.3
Thus, a polar solvent with less dielectric constant is used for precipitation of DNA. i.e. Ethanol.!!
Hope it helped :)
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I can see two questions here. “Why do we extract DNA?” and “Why do we extract DNA from tissue instead of from other material?
The first is simple. We extract DNA from cells for the same reason why we extract iron from ore. Knitting DNA socks from cells is hard.
The second is just as easy to answer. We extract DNA from tissue because that’s the best source.
I can see two questions here. “Why do we extract DNA?” and “Why do we extract DNA from tissue instead of from other material?
The first is simple. We extract DNA from cells for the same reason why we extract iron from ore. Knitting DNA socks from cells is hard.
The second is just as easy to answer. We extract DNA from tissue because that’s the best source.
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