Why does the PCR reaction catalyzed by the Taq DNA polymerase have a higher mutation rate than the normal DNA?
366393
Taq polymerase has a higher mutation rate during DNA synthesis because the enzyme lacks 3' to 5' exonuclease activity (ie: the enzyme lacks the ability to detect and repair base mis-matches).  To increase the fidelity of the PCR product, one should use an enzyme capable of proof-reading activity such as Pwo polymerase.
881107
A point mutation occurs in one nucleotide molecule in its triplet codon of 3 nucletides. One of the base pairs is change. For example adenine could become thymadine. This would result in a change of one codon. which if not corrected would change the paticular amino acid of the codon and could affect the protein that the amino acid is a part of. For example a codon coding for a particular amino acid could chacnge to a stop codon and chop off (truncate), the protein at that point resulting in a shortened useless protein.Such mutations cause certain types of mucular dystrophy etc. Point mutations are a  sources of genetic change. and a minority of those chacnges are positive althogh most are neutral ir deleterious. Cosmic rays can cause point mutations. Also carcinogenic chemicals, old age ionising radiation and certain chemicals. (e.g. 5 fluoro uracil etc.)\nDoc. Dan.
1104927
read here\n\nhttp://en.wikipedia.org/wiki/Mutation
521716
It can be right because resonance can occur and cause that the hydrogen bonds link to another base ( that will cause a mutation). However there will be enzymes to correct that error. And some U residues are methylated so they cannot join to adenine.
394858
It forms soluble complexes with dNTP and the DNA template to produce the substance the substrate actually recognises.It activates the buffer solution so that PCR can take place.If Magnesium ions which are needed for activation are not present, pcr cannot happen.
277848
No clue yet on this one. But leading research is showing that this may be a random event because of chromosome breakage. I would look into telomerase extension if I were you. Most of the time this is bad (Double stranded DNA breaks), but it happens all of the time (but luckily we have a good DNA repair system, I believe there are well over 1000 breaks a day and all we need is 1 for some bad genetic disease)
653691
I believe the difference is that in real-time PCR, when the first series runs, a second is started, where in Nested PCR, the primers, proteins etc are added a little at a time, making the process continuous, as opposed to in starts and stops.
249261
I do not specifically know names of species but spore forming bacteria do so to stand the unfavourable temeratures. The spores are very protective and can withstand a range of harsh conditions. \n\nThe difference with thermophillic bacteria (heat loving as some would say) is that these ones are dwell quite happily at high temperatues and do not need to form spores. There are some of these that live in hydrothermal vents at temperatures of greater that 70 degrees celsius and for that reason they are called extremophiles. Imagine, they can even replicate. In fact, an enzyme called Taq Polymerase is found in these bacterial species and due to its ability to work fine at high temperatures, it is used in a biotochenological procedure called Polymerase Chain Reaction (PCR) where it replicates DNA at greater that 60 degrees celsius. So the difference is the spore forming bacteria do not like high temperature and the thermophillic ones just love it!
597037
I dont know if this is it, but go here at: http://www.ks.uiuc.edu/Research/pro_DNA/ster_horm_rec/
307678
It affects us at the DNA level by increasing the level of mutations.  These mutations can cause abnormal growths, cancerous cells, & other unpleasant things.\n\nHowever it is possible that some of these mutations could be benificial.
1087349
One good one:\n\nDNA replication is much more resistant to errors ... so DNA molecules can be *much* longer than RNA and still survive replication.  This supports the stable propagation of a much larger number of genes (tens of thousands of genes) from generation to generation without degradation.
848007
You get a continuous and discontinuous strand because DNA polymerase only makes DNA in 1 direction (5` to 3`).  The continuous strand is in that orientation anyway, so you get a nice long replication.  The opposit strand is oriented 3` to 5` relative to the polymerase, so the replication has to be broken down into multiple, short, 5` to 3` segments so that replication can occur within the same polymerase macromolecule.\n\nI had to mention  DNA polymerase, it's really impossible to explain this without saying something about how it works :P I did leave out RNA primers though!  If anyone else is curious, the RNA primers are the site of the initiation of replication of each little Okazaki fragment.
230567
If the two processes don't copy the templates exactly everytime, that leads to mutations in the following strand.  If there are mutations, that leads to different properties of the proteins made in translation.  Depending on the mutation, this can have either a beneficial or very adverse effect, or even none at all, depending on where the mutation is, and if different amino acids are used.\n\nFor example, sickle cell anemia is caused by a single mutation.  Genotypically, one nucleotide is substituted for another, leading to a different amino acid.  Phenotypically, this different amino acid causes different bonding patterns in the hemoglobin protein, causing red blood cells to sickle.
736773
There are too many things that might have gone wrong.\nYou are saying your template is a genomic DNA and then that it is plasmid ("if I shouldn't use a plasmid DNA") ? It can't be both, unless you mean you have a genomic library in a plasmid...\n\nplasmid templates are very good for PCR so that is definitely not the problem.(Unless the plasmid preparation is not good and you have e.g some ethanol or isopropanol or whatever in it.)\n\nIf you meant that you have a choice between genomic and plasmid template  go for the plasmid \nYou have to check again the design of your primers, the putative Tm, the size of the DNA so that you let elongation occur for enough time, etc...\n\nSome polymerases cannot cope with very long and difficult templates under usual conditions so you might have play with the conditions or change polymerase or use a polymerase mix.\n\nWe don't have enough info to be more specific. You just have to go through the design again carefully to see if there are any mistakes and then start changing conditions (Temperature, Mg concentration, annealing temperature varying with cycles, polymerase, etc)\n\nAlso if you designed the primers based on the cDNA but the template has introns, did you check that there are no introns disturbing the sequence which the primers should be annealing to?
191717
This is the melting temperature for a particular oligonucleotide. This temperature is important for producing a successful polymerase chain reaction product. Depending on the sequence of your oligomer primer you will have to use various temeratures to ensure that they anneal properly to the target sequence.
644978
a mutation can change the DNA but not the amino acid sequence because in order to get a protein there are several options for DNA. (for example) you can UAG as a protein and you can get that by ATG, CGC, AUC and more.  So that gives you a chance to get the same amino acid with a change in the DNA.
574626
Interesting question about microbiology. Some recent studies have suggested that many people have a genetic mutation that may result in longer lives.  This mutation is in the mitochrondrial DNA.  You might check out the following websites for more information: www.wired.com/news/medtech and www.imminst.org \nThese sites may go into more detail as to the pathophysiology of the mutation.