RNA, or ribonucleic acid, is a biological macromolecule made of nucleotides used in cells to convey genetic information to protein. RNA also plays a role in catalyzing certain biological reactions as well as carrying genetic material in some viruses.

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Why is uracil used in RNA rather than thymine?

What is the advantage gained by the substitution of thymine with uracil? I have read previously that it is due to thymine being "better protected" and therefore more suited to the storage role of ...
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Why do eukaryotic organisms have introns in their DNA?

We touched on introns and exons in my bio class, but unfortunately we didn't really talk about why Eukaryotes have introns. It would seem they would have to have some purpose since prokaryotes do not ...
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768 views

How is RNAse contamination in RNA based experiments prevented?

Does anyone have any suggestions to prevent RNAse contamination when working with RNA? I tend to have issues with degradation regardless of whether I use DEPC treated / RNAse free water and filtered ...
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How long can I store extracted RNA?

If I extract RNA from a (leaf tissue) sample using a one-step phenol:chloroform extraction, how long can those samples be stored at -80°C? And how many times can I defrost and refreeze them before ...
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Can methylation from DNA get copied to RNA during transcription?

Methylation on gene-body and 3'UTRs if copied to mRNA can potentially regulate post-transcription modifications or expression regulation. But I'm not sure if they are maintained after transcription or ...
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What implications has the missing 2'-OH on the capability of DNA to form 3D structures?

The chemical difference between RNA and DNA is the missing 2'-hydroxyl group in the nucleotides that build DNA. The major effect of that change that I know of is the higher stability of DNA compared ...
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246 views

Can DNA act as a translation substrate?

I get conflicting answers. One would think if it was true, it would be rather seminal and widely known. There are papers from Khorana[1], Holland[2], and Bretscher[3] (late 60s) that suggest that it ...
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How do I clean phenol contaminated RNA without losing any of the sample?

I recently extracted RNA from developing plant leaves for the first time, as part of a very long and intensive experiment. The samples were extremely precious because of the amount of effort that went ...
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176 views

Can DNA produce ribozyme-like structures?

RNA is known to act as an enzyme via its ability to fold itself in specific ways. Is DNA capable of such structures? Or is it some biochemical reason stopping the folding? Have they been observed in ...
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Which sequence characteristics influence the transcription efficiency of T7 polymerase?

The T7 polymerase doesn't transcribe all sequences equally well, the transciption efficiency can vary widely for different sequences. One well known requirement of the T7 polymerase is that the ...
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Absorption ratios 260/280 and 260/230 for RNA

I extracted RNA from different cell lines, an I want to perform reverse transcription and then PCR. To get good results, in which range should the absorption ratios 260/280 nm and 260/230 nm be? And ...
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Why does RNA adopt an A-form helix?

RNA is known to form an A-form helix, while DNA generally forms a B-form helix under physiological conditions. From left to right: A-form DNA, B-form DNA, Z-form DNA. Image created by Richard ...
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First RNA polymerase-mRNA

We know that RNA polymerase produces mRNA by reading DNA strand. Which enzyme produces the first RNA polymerase if other RNA polymerases are synthesized in the same way like other enzymes(proteins) ?
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How does a single-stranded RNA bind to a double-stranded DNA to form a “triplex structure”?

If you have a single-stranded RNA that is complementary to a double-stranded DNA, how do they interact to form what my prof. calls a "triplex structure"? e.g. ...
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circulating microRNAs are functional?

In plasma and other body fluids, miRNAs can be found. They not only originate from dying cells but also from active secretion and are usually 'packed' into vesicles/lipo-proteic structures (i.e. ...
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Purpose of poly(A)+ RNA?

I am learning RNA-seq analysis. I always encounter this phase "poly(A)+ RNA". After searching, I got this: "Most messenger RNAs contain a poly(A) tail, while structural RNAs do not. Poly(A) selection ...
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716 views

Reverse transcription PCR optimization

What is the ideal amount of RNA to use for the RT? and how much cDNA to use then for the PCR? I did RT with a solution of RNA of 0.36 ug/ul. Then for my PCR I used 1 ul of the cDNA obtained and used ...
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Does RNA polymerase move around DNA or does DNA rotate benath the polymerase?

I'm thinking of the human genome specfically, but more general answers are welcome. As RNA polymerase moves along the DNA helix it follows a single strand. The two DNA strands are unwound locally ...
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Why do DNA and RNA have the functions they have?

I know that there are two most important directions of genetic information transfer in living organisms: DNA->DNA and DNA->RNA. The first is replication, and the second is transcription. I wonder if ...
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What is the function of the RNA primer in DNA replication?

During DNA replication, RNA primase puts an RNA primer in the lagging strand. What is the function of this RNA primer? Why can't the enzymes put DNA fragments directly?
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Very high 260/230 absorbance ratio of an RNA sample

After my most recent RNA extraction, the RNA samples had very high 260/230 absorbance ratios, (ranging from 5 to 25). I've never gotten numbers like this and I know the ratio is supposed to be ~2 in ...
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68 views

Can two hammerhead ribozymes simultaneously cleave each other?

I am working on a project in which an XOR gate is being built by having two hammerhead ribozymes simultaneously cleave each other when both are expressed, but have these ribozymes cleave a target ...
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222 views

Are some non-coding RNA spliced?

Are some non-coding RNA spliced like mRNA? I tried to find some information but I don't find anything...
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Does ethanol destroy RNase?

I've gotten conflicting advice on this: some people believe one can remove RNase contamination simply by spraying the bench, pipettes, gloves, etc. with ethanol. Others think ethanol does not destroy ...
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Do thymine and uracil ever appear in the same strand of RNA?

Wikipedia says that "in RNA, thymine is replaced with uracil in most cases." I'm curious what are the cases when this does not happen? Does this ever occur in normal functioning, or is it an error? ...
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Is wiping with RNAse Zap enough to destroy RNAse activity?

From the RNAseZap MSDS, it is an SDS at some unknown concentration, maybe with some NaOH? Some other links suggest there is some NaOH as well. The Ambion site states that RNAseZap destroys RNAse ...
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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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What makes DNA helical?

Why isn't DNA like RNA; why isn't RNA like DNA, that is, helical? Why are RNA chains straight?
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Do miRNA and antisense RNA do essentially the same thing?

Don't they both just disrupt RNA so it can't make a protein? If so, then what is the difference between the 2?
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Ribosomal RNA amount in a Drosophila cell

I am isolation RNA from Drosophila larvae brain with TRIzol method. What percentage of extracted RNA will be ribosomal RNA? I am only interested in mRNA, so I am trying to figure out whether I need to ...
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47 views

RNA-seq Data on domestic animal with different environment

I want to find the RNAseq data available on domestic animals in different environments. If microarray data is available, it would be more useful. If you know I would appreciate to inform me.
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317 views

Does bleach destroy RNAse activity, and if so, how does it do it?

I am working with RNA samples, and I'm trying to be very careful about RNAse contamination. I have some questions about bleach, though. Some people say that a solution of bleach is enough to destroy ...
4
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1answer
48 views

Finding RNA Loops

I was rooting through the literature, but there is too much work on the topic of detecting loops in RNA and the RNA helices that go with them. Can anyone point to a good review on this topic or even ...
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68 views

How predictably will RNA polymerase not translate repetitive sequences?

I am working on an (expensive) synthetic construct, which happens to have many "repetitive" sequences within it that are integral to its function. Primarily, the two sequences that are worrying me ...
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Are there any strictly chloroplast/mitochondrion-residing ribozymes?

A simple question that had occurred to me. Considering the small doubt of transcribed genes in both organelles, I would doubt it, but are there any known ribozymes strictly found in either ...
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Telomerase in tetrahymena

In this amazing video, at 26:03 we see this image We now know that the telomerase contains a sequence complementary to the telomere sequence and so is able to do what it is capable of doing in this ...
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Current state of direct RNA sequencing

I had a colleague ask me recently whether mRNAs could be sequenced directly. I found this Nature paper[1] published by Helicos in 2009, in which they describe their developments in the area. It's been ...
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How significant is RNA degradation with removal of cap/polyA's in eukaryotes, or UTR's in prokaryotes?

Question is rather self-explanatory, but segmented into two parts. I'm attempting to make use of a repression system that employs cleaving RNA at specific areas with ribozymes with the intent of ...
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1answer
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Majority of transcripts are from sense strand?

I am wondering whether majority of transcripts are transcribed from the 5'->3' strand? Because I encounter a lot of expressions like "anti-sense transcripts". Could anybody help clarify this? Thanks.
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Bioinformatics tool for “pairwise alignment” of complementary sequences?

I'm currently working on some ribozyme binding, and I'm looking for a tool that will essentially analyze the regions of the degree of complementarity in two sequences in order to extrapolate ...
3
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2answers
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Do RNA molecules bind each other?

I have a question, maybe a naive one. Let's assume that we isolated some RNA from a tissue. Do RNA molecules can bind each other if they have the complementary sequence? I know that some small RNA ...
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Detecting Introns and Exons

I know that when RNA is transcribed from the original strand of DNA it contains introns and exons, and that the introns are spliced out of the strand to provide genetic diversity. However, what I ...
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How are atoms in benzopyridines and benzopurines numbered?

I am well-aware of the numbering system used for the traditional bases, as seen below. My question is how are the atoms in the size-expanded bases seen in xDNA and xRNA numbered?
3
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Precursor miRNA and a mature miRNA

What is the main difference between a precursor miRNA and a mature miRNA? It is often the case that we have more than one precursor miRNA but only one mature miRNA. The miRNA-seq data contains only ...
3
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1answer
49 views

Can we attack viruses by attaching proteins and such to their shells?

Haven't looked into this to very long, but an initial search didn't return anything. HIV uses certain co-receptors to enter our cells. Could we flood the blood stream with specially designed ...
3
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1answer
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What's the use of RNA editing in kinetoplast?

The genes of the mitochondrion (kinetoplast) of some Kinetoplastida - e.g. Trypanosoma brucei, the parasite which causes African sleeping sickness - are "encoded" in a way that the pre mRNA requiries ...
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35 views

Is there any database with RNA classification?

I am looking for a database that would provide classification of various types of RNA - information about its structure, function, etc.
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Knockdown of long noncoding RNA (lncRNA) - how is it done?

I don't work at the wet lab and don't know all the details about the knockdown techniques. My question is: How lncRNA knockdown is done? For example - you have lncRNA that is functional in the ...
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Remove RNAse from pipettes?

Our lab uses old Gilson Pipetman pipettes. I've been using some for making mRNA by in vitro transcription and started running into RNAse issues. I'm trying to clean everything up, including the ...
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Process of Transcription

During the process of Conversion to Ribonucleoside Monophosphates the various ribonucleoside triphosphates break off their high energy bonds after linkage to the DNA.But the first ribonucleotide ...