Biology Stack Exchange
Biology Stack Exchange

Questions tagged [dna-isolation]

The laboratory technique involving the extraction of DNA from a cell in a pure form.

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How to DIY preserve pet DNA today so that it can be used in 20 years

I know that there are companies that offer a kit+storage of your pet DNA for around $2k. My question is if there is any other option for doing this yourself with a thought in mind that in 20+ years the technology will get so advanced that even this…
Registered User
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Why do we add salt when precipitating DNA?

All the DNA extraction protocols I have seen involve adding salts to the extraction buffer. What is the purpose of the salts? What happens if they aren't included?
Rik Smith-Unna
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Would it be possible to sequence human DNA from wastewater treatment plants?

I know that there are some efforts from scientists working with bladder cancer to perform liquid biopsy from urine for detection and monitoring of the cancer such as this one. I've been searching online - but the "wastewater" search term gives me…
ilam engl
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What is causing my problem with very low yields when isolating a 42kb yeast plasmid?

I have to isolate a large plasmid from yeast and transform it in E. coli. After transformation, I often get no colonies. One reason for that is the yeast mini prep hasn't worked or the DNA concentration is too low. I tried two different isolation…
Gergana Vandova
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Extracting cell-free DNA

Has anybody had any success in extracting cell free DNA from plasma without using expensive kits? I've already spent a lot of my own blood trying to use standard phenol/chloroform methods with very minimal yield. I know it's possible that since I am…
Jack
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What are the roles of guanidine-HCl and ethanol in binding of DNA to silica?

I'm trying to understand how exactly the binding to silica gel (in kits) step works and I cannot find any papers which provide an explanation of the physics or chemistry; especially on the way that Guanidine-HCl works. So lets get them from the…
F.N
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How bad is ethidium bromide in your plasmid for downstream applications?

I want to transfect Adipose Derived stem cells using a clone of my own. My problem is that I get a lot of contamination (not only genomic, but due to the nature of the technique, I get undesired products I haven't been able to get rid of). So I was…
Varekai
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Origin of the 260/280 ratio?

This is not a duplicate of all the other 260/280 ratio questions, I already know that DNA is supposed to be 1.8 and RNA is supposed to be 2.0. However, this might be more appropriate for chemistry, and will move it if I have to. My question has to…
user137
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How do I prepare and clone from E. coli DNA?

I'm looking for a protocol to get genomic DNA from an E. coli sample so that I can clone a small portion of it using PCR into a plasmid. (< 500 bp in this case). It seems OWW (Open Wet Ware) only discusses preparation of fragmented DNA. Does this…
shigeta
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What is a good miniprep protocol for the class room?

I'm trying to find a good protocol for plasmid minipreps and I'm looking at 3 preps I've found: Using phenol/chloroform extract with phenol:chloroform:isoamylalcohol, isopropanol precipitation, 12,000g spin down, rinse with cold 70% ethanol.…
shigeta
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Appropriate Buffer for electerophoresis of DNA & Protein TBE or TAE?

Which buffer is best for DNA Electrophoresis and which is best for Protein to be have a sharp bond? Considering a higher electrical conductivity compared to TAE & TBE and the generation of less heat. If anyone has a particular formulation (add other…
M007
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DNA extraction from oil-containing seeds

Which protocol of DNA extraction from plant oil-containing seeds take fast and good result in purity that can use in RT-PCR(Real Time polymerase chain reaction)?
M007
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NaCl role in CTAB - DNA complex in DNA extraction

I have a question about the role of NaCl in the DNA extraction process. So for NaCl concentrations under 0.5M, CTAB and DNA molecules can create complexes. In those concentrations, proteins and other hydrocarbons are still soluble in water except…
F.N
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Microsatellites and Minisatellites: Which of these form the basis of DNA fingerprinting?

I'm in a fix. Prepare yourself for a long read We've just learned about minisatellites and microsatellites at class (okay, by "learned", I mean we were told their definitions and essentially nothing else... hardly surprising, since we aren't…
paracetamol
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Why are large amounts of DNA required for analysis?

I know PCR is used to create large amounts of copies of genes and that it's a scientific breakthrough but want to understand why. Why do we need large amounts of DNA to be able to analyse it, to utilise it. Isn't a single DNA molecule enough?
Edward Garemo
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