Posts Tagged ‘used’
Last Updated on Thursday, 19 May 2011 12:34 Written by Administrator Thursday, 19 May 2011 12:34
Question by Shae J: what are three situations where only minute DNA samples are available for sampling and PCR could be used?
Best answer:
Answer by academicjoq
Forensic investigations (crimes where only a cell or two is found)
paleontology
plane crashes
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Last Updated on Tuesday, 17 May 2011 04:31 Written by Administrator Tuesday, 17 May 2011 04:31
Question by Anthorien: What methods can be used to confirm a PCR product is not a non-specific amplification product.?
Best answer:
Answer by Theruchet
If you have a sequence of complementary DNA, RNA or a protein that is known to bind to the sequence of DNA that you were trying to polymerize then you could combine them and see if they do bind. Methods may vary to see if they do bind the DNA… here are a couple ideas:
1. the DNA, RNA or protein can be grown with a fluorescent or radioactice label attached. Then you would simply have to wash off your product (say run it through a gel filtration or affinity column) and see if the label remains.
2. If you know of a binding assay using a chromogenic substrate or a substrate with a known absorbance (that’s NOT the same as DNA absorbances…) you could perform this assay to see if the absorbance changes (absorbance usually changes by a measurable amount when a chromogenic substrate binds to another molecule).
This has been assuming that you’re polymerizing DNA. If you’re doing RNA just replace DNA with RNA everywhere I said it. I hope this is useful.
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Tags: Amplification, confirm, Methods, nonspecific, product, used | Posted under PCR Polymerase Chain Reaction Forum - Troubleshooting Questions & Answers | 1 Comment
Last Updated on Saturday, 14 May 2011 08:31 Written by Administrator Saturday, 14 May 2011 08:31
Question by sikka_5: HELP ON BIOLOGY. what is used in PCR?
is cDNA used in PCR? is DNA ligase used in PCR? (polymerase chain reaction)
Does the order go as follows?
1. Add cDNA
2. heat
3. Add polymerase and primers?
Best answer:
Answer by kookoo
Hello 
There are basically four important elements in PCR:
1. Targeted DNA Strand. The whole DNA strand. Without it you wouldn’t have anything to copy.
2. DNA Primers which are complementary to the 5′ to 3′ of the DNA strand.
3. DNA Polymerase. To aid in the addition of nucleotides to the chain.
4. Complementary nucleotides: dATP, dTTP, dGTP, and dCTP.
No cDNAs are used, instead what is used is the synthesized group of dNTP, where N is either A, T, G, or C.
DNA ligase is not needed as the alternating high and low temperatures help the Primer and Nucleotides to hydrogen bond naturally.
EDIT:
I’m sorry I don’t know the sequence if you’re using cDNA…but yeah, if the cDNA is the template then it should be in that order…
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Tags: Biology, help, used | Posted under PCR Polymerase Chain Reaction Forum - Troubleshooting Questions & Answers | 1 Comment
Last Updated on Friday, 13 May 2011 12:31 Written by Administrator Friday, 13 May 2011 12:31
Question by nikebball023: why should primers used in a PCR reaction have approximately the same Tm?
Best answer:
Answer by Steve is knowledge
Because that way the primers anneal at approximately the same temperature and the reaction can occur simultaneously for both primers.
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Tags: approximately, primers, Reaction, same, should, used | Posted under PCR Polymerase Chain Reaction Forum - Troubleshooting Questions & Answers | Comments Off