The process in which the DNA sequence of all or part of an organism's genome is obtained.

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What exactly are computers used for in DNA sequencing?

I've thoroughly read the Wikipedia article on DNA sequencing and can't get one thing. There's some hardcore chemistry involved in the process that somehow splits the DNA and then isolates its parts. ...
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272 views

Why was it so hard to decode the corn genome?

My teachers growing up told me it was impossible to decode the maize genome. But yet its been done. Why was decoding the genome so significant, and what made it so difficult?
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410 views

Why did high A+T content create problems for the Plasmodium falciparum genome project?

The main paper for the Plasmodium palciparum genome project (Gardner et al., 2002) repeatedly mentioned that the unusually high A+T content (~80%) of the genome caused problems. For example they imply ...
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396 views

Questions to ask to a panel of people that will be sequenced

Some genes have been shown to be associated with left-handedness. Working with some clinicians, I've recommend them to ask their patients (whose genome will be sequenced) if they are "right or ...
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681 views

Why do restriction enzymes tend to have an even number of bases in their recognition site?

When reading my textbook I noticed that in all examples but one from eight the recognition site was an even number of bases. I wondered if this was just a co-incidence, so I took the data from this ...
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323 views

Why are there N's after Sanger sequencing?

After sending a DNA sample for sequencing, the resulting sequence had N's in the beginning and end of the sequence. I know the N's mean that the computer can't tell what the base pair is, but why is ...
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538 views

Sequencing the genomes of polyploid organisms

I've done some transcriptomics work in the past with a polyploid organism, and this presented some unique challenges in the data processing and analysis. Since then, I have been brainstorming about ...
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344 views

Looking for a cancer drug target database to guide sequencing of patient tumor DNA

I have a question I would like to pose to the community. I have recently received access to a bench-top ion torrent DNA sequencer. Our idea is to use this machine to sequence the DNA from patient’s ...
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306 views

What are the limitations to current nucleotide sequencing technologies?

Using the Illumina platform, it is cheap and (relatively) easy to sequence huge amounts of DNA or RNA. There are various other platforms out there (Roche/454, SOLiD, PacBio, Ion Torrent) each with ...
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161 views

protocol for pulldown of DNA breakpoints?

Is there any method to do pulldown enrichment of DNA breakpoints from a cell? I have found this paper reporting a method to enrich for the DNA single-strand breakpoints from meiotic recombination ...
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Is there any difference in terms of personal healthcare between complete DNA sequencing and SNPs genotyping?

There are several companies (most notably 23andMe) providing SNP genotyping for individuals claiming that there is no sense for individual in obtaining full genome sequence since only small part of it ...
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5k views

What is the difference between SOLiD, 454, and Illumina next-gen sequencing?

I've started teaching myself about next-generation sequencing in preparation for a new job, and I'm wondering what the main differences are between the 454, SOLiD, and Illumina/Solexa machines, in ...
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479 views

BLAST DNA Sequences Reversed

I have been trying to learn some basic DNA sequencing techniques and have been using BLAST as a reference. I thought that I was starting to get it, but then I cam across this: It looks like it's ...
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1answer
689 views

Digital Genomic Footprinting for ENCODE

I'm reading over the ENCODE Nature papers, and one of the papers referred to is "Global mapping of protein-DNA interactions in vivo by digital" by Hesselberth et al[1]. Genomic footprinting is a ...
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456 views

Finding proteins in DNA sequence

I have to do a task for a university task and I need to understand some things before figuring out how to do it. The task is the following: Find matches of known proteins (DNA-PolyI,II,III) to ...
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160 views

Alternate genetic codes in newly sequenced organisms

Variations of the standard genetic code are pretty rare, but as the cost of high-throughput genome sequencing continues to drop, there is a greater possibility of discovering additional exceptions. ...
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727 views

How to clone and sequence a gene transcript of unknown sequence?

How might I go about amplifying a gene transcript (mRNA) from animal tissue of which little is known about the genome? In some applications, I have used reverse transcriptase PCR to amplify all mRNA ...
7
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1answer
524 views

ChIP-seq vs ChIP-exo

I'm currently investigating ChIP-seq vs. ChIP-exo for finding binding sites. As far as I can tell, ChIP-exo seems to be better in every way than ChIP-seq... but then again, I'm not strong in this ...
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58 views

Sequence of ribosomal RNA

Is it possible to sequence rRNA directly, that is, using the ribosome rather than the DNA from the nucleus? For example, this paper, Complete nucleotide sequence of a 16s rRNA gene from E. coli, ...
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65 views

How are whole Haplotypes for Sequencing isolated?

Is it possible to reliably isolate and amplify DNA from individual sperm and/or eggs (from a fish)? I'd imagine that the small amount of DNA would make the PCR a bit wacky. We've considered ...
6
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536 views

Looking for a DNA sequence

I am not a biologist. Please pardon me, if my question does not make sense. I am trying to obtain a DNA sequence for pattern analysis in Matlab. I used to generate random sequence ...
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3answers
336 views

What's the use of DNA sequencing results?

Suppose I sequence DNA of some organism (a human perhaphs) and now I have the entire DNA "string" - the sequence of nucleotides. What's the use of that? It's just a "string" where nucleotides encode ...
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187 views

Can I compare Shannon indices of metagenome gene data?

I'm comparing 12 Metagenomes. I'm using HMM counts of a number of proteins known to exists as groups within certain operons. I have grouped the HMM counts for each type of operon and calculated the ...
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96 views

Mechanics of going from DNA sequence to metabolic network

My apologies for possibly a naive question. I'm a statistics type and have been asked to assist with analysis of metabolic pathways (and networks). However, I would like to have at least a layman's ...
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1answer
178 views

Is there a detectable amount of bacterial DNA in the blood of infected persons?

With which bacterial infection in humans has it been shown that bacterial DNA can be found in the blood? If any is found it is likely not to be very much, and even difficult to distinguish from ...
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How do we know that everybody's DNA fingerprint is unique?

How do we know that everybody's DNA fingerprint is unique? I know, I know, everybody's DNA is unique. But when we do DNA fingerprinting, we're looking at very specific regions of high variability. ...
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How easy is it to carry out de novo sequence assembly?

Today a colleague of mine asked the following question: " Assuming I need to build from 0, a chromosome of a fish, with short reads but no other reference whatsoever [de novo assembly]: ...
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159 views

What are the limitations of commercial-grade DNA genotyping compared to full sequencing?

I've heard about services like 23andme, which offer genetic testing to the general public. As a person who knows very little about genetics, I'm interested in the subject and would like to know what ...
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109 views

introduction to Chip Seq

I hope this question is suitable for this site. I am concerned about the Chip experiment part so I think it should be okay. I am a Applied Math student starting to get into bioinformatics and so I've ...
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1answer
85 views

What causes DNA to skew in gel electrophoresis?

In gel electrophoresis, what causes effects like these (see collumn 11 in the first one, an collumn 6 in the second). ? (These images were samples that I took from an online activity we did for ...
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3k views

What's the difference between shotgun sequencing and clone based sequencing?

What are the main differences between shotgun sequencing and clone based sequencing?
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1answer
117 views

Is it possible to sequence only the 16S rRNA component? If so, how?

There have recently been several papers on using 16S rRNA as a way of identifying species (here, and here). I'm wondering if it's possible to sequence either just that subunit of the ribosome or just ...
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243 views

Tool for nucleotide alignment with all nucleotide codes (e.g. R, Y, W, S, etc.)?

I have a vector sequence and would like to find the following nucleotide sequence in it. AASYWSRA This query sequence uses several degenerate symbols, defined ...
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101 views

How to create a collection of anonymous sequences for teaching and testing? [closed]

I am looking for a large collection (>1000) of sequence files (eg. FASTA) from any real organism or a tool to create such a collection. The sequence files would be used for teaching and for testing ...
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140 views

Why do we need deep sequencing?

Why do we need deep sequencing? Why cannot the sequencing technologies read all the nucleotides correctly at the first read? Sorry since this question is too trivial, I don't have a biological ...
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111 views

Sequencing from PCR

As far as I understand it, PCR can be used to make many copies of one gene. My question is, is it possible to sequence DNA after PCR and is it easier than sequencing it via other methods. If it is ...
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106 views

How to calculate extent of Sequence similarity

I had a problem that I was wondering if it could be solved by one of the techniques/algorithms used in bioinformatics to give the extent of similarity. I have a Problem Statement: we have a sensor ...
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Reference sequence for defining single nucleotide polymorphisms

Single nucleotide polymorphism (SNP) or genetic variation in general, by definition are relative to a reference sequence. When we talk about databases of SNP as in ("dbSNP—Database for Single ...
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Detecting cancer or a genetic predisposition based on DNA sequencing

I am not by any means a biologist - so go easy. What would be a method for determining whether or not a patient has cancer based only on a genomic sequence? Update Thanks for the help in revising ...
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309 views

What species have had their genomes sequenced/are being sequenced?

The human genome project released it's first complete genome nearly ten years ago. Since then many species have also been sequenced. I am trying to find a list of completed (and possibly ...
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1answer
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Results of a complete DNA sequencing - are they 100% reusable?

Is that correct that a complete DNA sequencing (the whole genome) need only to be done once (per person)? After that is done, it the complete genome can be stored and once the new genes (and they ...
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42 views

Is it possible to clone a Neanderthal?

As Neanderthal DNA has been sequenced, is it possible to create a living Neanderthal?
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64 views

What is meant by single molecule sequencing?

When sequencing papers refer to single molecule sequencing, what is their definition of a "molecule". Are they saying base by base? The entire DNA chain in a chromosome can also be though of as a ...
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Why only heterogeneous SNVs for validation using genotyping arrays?

I am trying to validate the variants I found using whole genome sequencing . The standard practice, I have seen in the two publications below were to check for the number of heterozygous SNPs called ...
3
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1answer
702 views

What is the purpose of Y-shaped adapters in Illumina sequencing?

Y adapters different sequences to be annealed to the 5' and 3' ends of each molecule in a library. The arms of the Y are unique, and the middle part, connected to the DNA fragment, is complementary. ...
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Is there a database containing sequences of human cell lines?

I'm looking for the whole genome sequences of several human cell lines, e.g., A549 or Ea.hy.926. Is there a database specifically dedicated to human cell lines?
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Sequencing rtPCR product

So I have a validated set of primers for rtPCR from Biorad that contains SYBR green. If I do rtPCR, can I use the rtPCR product after purifying it with a Qiagen PCR purification kit? Also, I'm under ...
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Comparative cost of RNA-seq vs sequencing full length cDNAs

I am in the process of assembling and annotating the genome of a non-model organism, using almost exclusively short read (paired-end Illumina) data. Throughput is one obvious benefit of these data ...
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94 views

Cheapest Way to Measure Germ Density

I would like to measure the surface density of Staphylococcus bacteria and Rhinoviruses (only those two, to be specific) within my home. What's the cheapest way? The textbook procedure is to: rub ...
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How were the first primers made

I keep reading about how primers are useful in pcr -- they allow you to select a specific dna region. Similarly, in NGS or Sanger sequencing they give you a starting point. The primers I see are about ...