Unveiling PCR Additives: Exploring Their Benefits

  • Thread starter Monique
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In summary, PCR can work fine without additives, but they are often helpful. MgCl2 and MgSO4 are often used to help stabilize secondary structures in DNA, while DMSO and formamide are polar solvents that help to solvate denatured DNA. Glycerol is also effective at solvating denatured DNA. Tween and spermazine are polyamines, and the last is a hydrazine linkage polyamine. Ammonium sulfate is just a salt.
  • #1
Monique
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OK, let's get some molecular biology in here. I would really like to know exactly how many PCR additives there are and why they would improve the reaction.

I am talking about reagents such as DMSO, Tween, Formamide, Glycerol, spermazin?, (NH4)2SO4 etc.


for those who don't know: PCR (polymerase chain reaction) is a technique that linearily or exponentially amplifies DNA, such as specific genes or 'just' the whole genome.
 
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  • #2
Wow!

There are PCR additives? Why? Seems to work fine without them doesn't it?

I did PCR today, and we used the usuall stuff (all of the nucleotides, Forawrd primer, reverse primer, Taq DNA polymerase..)

Oh, there they are...
we used Tris HCL pH 8.8, MgCl2 and... here it is : (NH4)2SO4

I ahve no idea what those three additives do. Obviously, MgCl2 is a salt, it probably does some salt binding thing with the DNA...but to what effect I don't know.

Thanks for posting this, I will ahve to ask why they are in there now.
 
  • #3
Would the Glycerol count as an oil? I know we added oil to stop the water from evaporating as it is heated through the cycles.
 
  • #4
Originally posted by Another God
Wow!

There are PCR additives? Why? Seems to work fine without them doesn't it?

There sure are And no, PCRs don't always work without them.. I have run into this problem the hard way. It is true that the standars PCR consists of the ingredients you describe.. but sometimes the primers are unstable on the sequence or the sequence is rich in secondary structures, that is when the additives come in.

Oh! I have to attend an seminar.. be back later.
 
  • #5
Additives such as glycerol, DMSO, betaine are very effective (you need luck as well), when your DNA has a high GC region. MgSO4 can be replacing MgCl2 when your GC porcentage is high due to it helps to destabilize secondary structures in DNA.
There should be more additives...let me think
 
  • #6
DMSO and formamide (N,N'-dimethylformamide, right?) are polar solvents, they'd help solvate denatured DNA. So would glycerol. Tween and spermazine? Never heard of them. Is the last a polyamine like spermidine? With a hydrazine linkage? Ammonium sulfate I imagine would just be a salting in efffect.
 

FAQ: Unveiling PCR Additives: Exploring Their Benefits

What is PCR and why is it important in scientific research?

PCR stands for Polymerase Chain Reaction, which is a technique used to amplify a small amount of DNA into a larger amount for analysis. It is important in scientific research because it allows for the rapid and accurate replication of DNA, making it a valuable tool in areas such as genetics, medicine, and forensics.

What are PCR additives and how do they affect the PCR process?

PCR additives are substances that are added to the PCR reaction mix to improve its efficiency and accuracy. These additives can help with DNA amplification, prevent contamination, and increase the specificity of the reaction. They can also improve the stability of the reaction and reduce the likelihood of errors.

What are the benefits of using PCR additives?

PCR additives have several benefits, including improving the sensitivity and specificity of the reaction, reducing the time and cost of the PCR process, and increasing the yield and quality of the amplified DNA. They can also help optimize the conditions for PCR, making it more efficient and reliable.

What are some common PCR additives and how are they used?

Some common PCR additives include betaine, DMSO, and BSA. Betaine is used to improve the amplification of GC-rich DNA, while DMSO can help prevent secondary structures from forming in the DNA template. BSA is often added to prevent enzymes from binding to non-specific sites on the DNA, increasing the specificity of the reaction.

Are there any potential drawbacks to using PCR additives?

While PCR additives can greatly improve the efficiency and accuracy of the PCR process, there are some potential drawbacks. Some additives may interfere with downstream applications, such as sequencing or cloning, and may need to be removed before proceeding. Additionally, the optimal concentration of each additive may vary depending on the specific PCR reaction, so it is important to carefully optimize the conditions for each experiment.

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