The CTAB extraction buffer is supplemented with PVP and 2-mercaptoethanol just prior to use during DNA isolation. What is the role of PVP and 2-mercaptoethanol in Plant genomic DNA isolation?
Plants are rich in phenolics compounds and for one to get a quality DNA these should be removed. Therefore, PVP (polyvinylpyrrolidone) is helps in removing phenolics by forming hydrogen bonds with them. while beta-mercaptoethanol is added most of the times in the extraction buffers is a strong reducing agent to clean tannins and other polyphenols present in the crude plant extract.
Higher concentrations of phenolic compounds can be removed by PVP (Polyphenolpyrollidine), during genomic DNA isolation.
Beta -mercaptoethanol is a strong reducing agent which can remove tannins and other polyphenols often present in the crude plant extract.
It may also help to denature proteins by breaking disulphide bonds between cysteine residues.
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https://www.researchgate.net/post/what_is_the_role_of_PVP_in_CTAB_buffer
The same question was discussed already.
Cotton is rich in the secondary metabolites,such as gossypol。Some of the secondary metabolites are easy to be oxidated and then combine with DNA while isolating DNA。β-mercaptoethanol is an antioxidant which can prevent the oxidation of the secondary metabolites。PVP can prevent the cohesion of the secondary metabolites and DNA。They can help us get high quality DNA。
Polyphenols binds the DNA quickly and makes the downstream processing like PCR and Restriction digestion difficult. Its oxidized product i.e. Quinone’s breaks the DNA by producing Reactive oxygen species. PVP removes the poly phenolic contamination by binding it through hydrogen bond,thus it prevent polyphenol oxidation and thereby the browning of the DNA samples .
Beta mercaptoethanol act as reducing agent
Dear Arvind,
I don't want to be unpolite, but to be honest, I wonder if this is a way to increase RG score, instead of the desire of asking and share something to/amongst collegues. A google search would give you plenty of informations on this topic. - as well as on other similar basic questions related to DNA extraction.
I apologize in advance if my answer somehow hurted anyone's susceptibility.
Dear Emidio,
I feel sharing in RG may give you more specific and relevant answers from the persons who are working in the same field.
PVP helps to remove polysaccharides where as 2-mercaptoethanol in polypehnolic compounds.
Polyvinylpyrrolidone (PVP) is used to remove negatively charged polysaccharides, which would otherwise chelate Mg2+ and Ca2+ ions required by most DNA modifying enzymes. DTT reduces S-S bonds in proteins, denaturing them, which would facilitate their removal from the DNA
PVP helps to remove phenolic compounds and B-Mercaptoethanol helps in breaking down the disulphide bonds in cysteine residues
PVP is used to bring out phenolics as phenolics at higher concentrations act as pro oxidants and can damage DNA. PVP also helps in removal of polysaccharides which can otherwise chelate metal ions and cause degradation of DNA. Mercaptoethanol is used to facilitate removal of proteins by linearising them. Such linearised proteins get entangled n messed up and get removed by following centrifugation step.
Mercaptoethanol is used as an antioxidant, especially for polyphenols which become insoluble when oxidised and tend to precipitate along with the DNA.
Thank you all .. answers are very useful to me too...thanks...
Joe, there are many DNA extraction protocols out there. choose one and follow its procedure
I have had a similar challenge getting DNA after using CTAB protocol. What percentage of pvp works for highly phenolic compounds?
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