The study of the molecular processes of the nucleus and cell function.

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In the life-cycle of the HIV virus, how does the created DNA enter the nuclear membrane?

I am in a high school biology class, so I cannot truly attest to how accurate the information I am given is, but as far as I know only RNA and very small molecules can enter the nuclear membrane ...
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19 views

What are flagged primers?

I'm interested in amplifying a sequence for further use with Gibson Assembly. I want to create overhang regions in my DNA fragment so there would be complementarity to the plasmid I'm trying to insert ...
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86 views

L-tryptophan in mammalian cell culture

Why must the concentration of L-tryptophan be kept to a relatively low level when culturing mammalian cells? It's an essential amino acid, so I cannot fathom why low concentrations as opposed to ...
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50 views

What Chemical Trigger Causes Ectomycorrhiza To Change From Asexual To Sexual?

I am searching for the catalyst behind the change of asexual to sexual ectomycorrhiza when symbiosis with a tree root is formed. As ectomycorrhiza attaches itself to a root, they form a relationship ...
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103 views

Can I leave BL21(DE3) cells in room temperature?

I am preparing competent cells, and I finished inoculating a single colony in SOB. It has been incubating at 37 degrees Celsius for almost 16 hours since, and it's getting very late where I live. I ...
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239 views

E. coli not growing in liquid medium

We are regularly doing bacterial transformation and subculture from plate to liquid media to extract DNA. This usually goes very well and is straightforward, but occasionally, the colonies that grew ...
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256 views

Storing Taqman plates with polymerase in fridge before running

I'm going to be running some Taqman assays on cDNA generated from RNA collected from various samples, and will end up running a bunch of plates (right now the setup is 1/2 a plate per sample, ...
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67 views

How does estrogen influence collagen synthesis?

Through what mechanisms does estrogen interact with collagen synthesis? Especially in the context of elevated estrogen levels and genesis of purpura simplex .
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175 views

How to prevent e coli from clumping (for FACS)?

I'm performing FACS on e coli, but the cells are clumping together so each event is multiple cells. I ran a control where I had one flask of e coli expressing GFP, and one flask expressing RFP. Run ...
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48 views

Is there a metabolic pathway that generates methanol?

I've been looking for help topics about methanol in metabolism. Specifically, I wish to know what is a common dietary component that generates methanol following metabolism and comment on its ...
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184 views

Gibson assembly using NeBuilder

I am supposed to construct a plasmid that contains features from two other plasmids. My strategy is to generate three fragments form the two other plasmids. I was encouraged to try Gibson assembly, ...
3
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41 views

Adenosine metabolism

Are adenosine or its catabolites increased in inflamed airways? How can I assess this? I am trying to use inhibitors for adenosine deaminase, xanthine oxidase, and purine nucleoside phosphorylase, but ...
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15 views

Do only one or both pairs of homologous chromatids exchange genetic material during the process of crossing over?

To be specific: Assume chromosomes A and B are homologous. They've both replicated into A1, A2 and B1, B2 and have formed a tetrad at the equator (synapsis). Most textbooks show either A1 and B1 OR A2 ...
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51 views

What is the advantage of using plant-derived antibacterials rather than bacteria-derived antibacterials?

So obviously we have a big problem with antibiotic resistance. Most of our antibiotics originate from bacteria themselves (or are synthetic variations on scaffolds which originate from bacteria). I ...
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31 views

PCR that worked previously is now only showing primer dimers and a smear on gel

PCR amplification of a promoter sequence for gel extraction worked beautifully using Phusion HF enzyme with GC (higher error but less picky) buffer. However, DNA concentration from the gel extraction ...
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28 views

Gel Electrophoresis

we add Etbr within the agarose gel but we do not add Etbr directly in native PAGE ?when we make agarose gel, we add Etbr before its solidification but we do not add Etbr when the native PAGE gel is in ...
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36 views

Why is there a size limit on inserts that a plasmid can accept?

Throughout my undergraduate education I have been taught that plasmids can't carry very large inserts, but I have never been told why. Any insight would be greatly appreciated.
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51 views

Why is A-U bond less stable than A-T bond?

I have encountered the following fact many times, but have not yet encountered a possible explanation for it. Will you please help me understand the molecular mechanism by which the bond between ...
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182 views

Why does supercoiled DNA run faster?

The DNA exists in linear and cirular forms. The latter form has interesting feature called Supercoiling. The more number of writhe makes it more supercoiled because of which it gets more compact. ...
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15 views

Why are multiple copies of the 35S enhancer used for overexpression in plants?

I know that the CaMV 35S promoter is widely used for transgenic plants, and I also know that it can be used as an enhancer element for overexpression. I noticed that it is always used as a ...
2
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53 views

PAGE gel in EtBr

I have been using TBE-PAGE gel to see small fragments of DNA by post-staining that means gel is stained with EtBr after electrophoresis. Someone told me that you can add EtBr before polymerizing ...
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26 views

Can mutation rate be increased for instance by mutagenesis targeting the DNA polymerase?

I am studying a non-cultivable bacterium living in an insect host, and I would like to generate some random mutants of this bacteria while preserving the insect. I am wondering if one way to do so ...
2
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158 views

How much salt [NaCl] is too much in DNA precipitation?

In DNA extractions, how much is too much salt in a CTAB extraction buffer? Protocols hover around 2.5 molar; if you go over this (e.g. 25 molar), will you saturate your solution, and precipitate the ...
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24 views

BSA for trouble shooting failed PCRs?

I am using PCR to amplify a 1000bp region of the CytB mt gene. Some of the samples had not amplified and I wish to change the reaction components (or use additives like BSA) to attempt at getting ...
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29 views

Does blood typing still provide a use for ancient tissue analysis?

Modern techniques. In recent years, DNA sequencing has become extremely cheap. This, compounded by the ability to PCR miniscule samples to viable samples for analysis, means that aDNA can be ...
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26 views

Can encoding of miRNAs in introns not cause dysregulation of gene expression?

For example, consider a gene X which has an intron which encodes a miRNA that downregulates expression of another gene Y. When the gene X is translated, this miRNA will appear as a byproduct of ...
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56 views

CRISPR Knock in

Using the CRISPR/Cas9 technology, it is possible that after inducing a DSB with the Cas9 endonuclease guided with an RNA designed by the user and using a template DNA, get a desired Knock-In (KI) by ...
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49 views

What is NK-cell compartments?

with respect to the paper: Adaptive reconfiguration of the human NK-cell compartment in response to cytomegalovirus: A different perspective of the host-pathogen interaction What is meant by ...
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56 views

Zinc and brewer's yeast

I'm hoping for some information relating to yeast nutrition (specifically Saccharomyces cerevisea) in beer fermentation. Zinc is well-known to be necessary for yeast cultures to perform successful ...
2
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22 views

Gene expression for mouse feeder cells (inactivated MEFs)

I'm looking for a paper with gene expression data for mouse feeder cells, inactivated by gamma radiation or mitomycin C. Ideally I'd like RNA-seq data but I'll use microarray data if that's all there ...
2
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18 views

Resource for finding Repressive/Inhibitory factors for a given gene?

I have a list of genes for each of which I'd like to find: A list of transcription factors that up-regulate the gene A list of inhibitory factors that down-regulate it. I used this tool on ...
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330 views

Image Processing Suite for bacterial microscopy: Schnitzcells or MicrobeTracker?

I am looking to start doing some work tracking the size and growth of individual bacterial cells in the microscope. In order to analyze the images I need software that can segment the cells, ...
2
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277 views

Can Pfx polymerase add only one 3' A overhang?

I am trying to clone a PCR product that was amplified using Pfx polymerase into pGemT vector. I had to A-tail the PCR product using Taq polymerase since Pfx only generates blunt end products. My ...
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12 views

How is “fine mapping of pelvic regulatory region” done in the stickleback PitX1 paper?

I'm working through this paper for a class. I'm a bit confused by the methods they used in one experiment. So the researchers are studying spine development in stickleback fish. They noticed some ...
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33 views

Which of the three is true for insulin receptors?

I have seen the following question in a Cell Biology exam: Which of the following is true" Insulin has an hydrophobic Signal Peptide and the insulin receptor does not have an hydrophobic ...
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39 views

Which DNA fragments do not have expected sizes on this gel electrophoresis?

The problem is such: After performing a PCR, the vector carrying the PCR fragment with two restriction enzymes (Nhe1 and Asc1). The DNA samples were then separated using agrose gel electrophoresis ...
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41 views

How does lactic acidosis lead to pain?

I come from Physics, not biology. My understanding is that without sufficient oxygen present, the Kreb's cycle terminates in lactic acid formation for the body to later continue the reaction when ...
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17 views

Yew seed dormancy reduction

Yew seeds have very long dormancy when artificially planted. They are also adapted to passage through digestive systems of animals that eat/transport them. But could the dormancy be shorter (or the ...
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41 views

Why do PCR manufacturers recommend assembling the reaction mix on ice?

Many PCR manufacturers recommend preparing the reaction mix for the reaction on ice. For example, here is NEB's recommendation for their Q5 polymerase. Other manufacturers also include similar steps: ...
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33 views

Can genes be expressed sequentially?

As I understand it, any gene on an exposed/unpacked region of a chromosome is continuously being expressed. Regulatory genes may increase or decrease the amount of protein synthesised due to its ...
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23 views

Is pathlength correction vital to be included while quantifying protein

I am trying to quantify protein in serum/plasma samples. I have carried out biuret assay for my samples using microplate reader. While performing I encountered the doubt whether I should include ...
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21 views

If two different diseases have more than one common pathway, the relationship between their occurences?

I just wonder that are there any special relationship between the pathway and disease occurrence. For example, there are cancer A and cancer B (and they have more than one common pathway). Then if ...
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20 views

How do molecular recognition features work?

The occurrence of relatively short (10–70 residues), loosely structured protein regions bind within longer, largely disordered sequences that were characterized as bound to larger proteins. These ...
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34 views

How are CheY, CheA, CheW, CheZ pronounced in speech?

This is a quick followup question to this question about proteins that play important roles in chemotaxis: How does one pronounce the protein names "CheY", "CheW", etc., in English? My guess would ...
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41 views

Protein modification and ATP consumption

According to wikipedia there exists a lot of ways to modify a protein (post-translationally). Just to mention few: phosphorylation, dephosphorylation, glycosylation... While phosphorylation requires ...
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51 views

Genetic mapping problem

A prototrophic Hfr strain of E. coli with the genotype trp+ purB- pyrC+ is conjugated with an F- strain with the genotype trp- purB+ pyrC- . The trp gene is known to enter last. The following numbers ...
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27 views

Is a Ribonuclease Inhibitor protein the only mechanism employed by the human cell to protect cellular RNA from degradation by endoribonuclease?

Are there any other methods of protection for cellular RNA from degradation by endonuclease (specifically the Pancreatic Ribonuclease RNase II (Eosinophil-derived neurotoxin) and RNase III (Eosinophil ...
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24 views

What is the lifetime of the vasopressin receptor V2?

I was looking at the production of vasopressin receptor 2, also known as V2R or ADH-R. What I found is that it is coded by the AVPR2 gene and degraded by the Alix protein (source). But I did not get ...
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145 views

Where do the H+ ions come from in light reactions?

In the light-dependent reactions of photosynthesis, H+ ions pass to the thylakoid space. Where do these protons come from?
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109 views

Recommend any Molecular lab LIMS (Laboratory Information Management System)

We are looking to develop or customize a LIMS for our molecular lab. Do you know of a LIMS that you've used in a molecular lab before, or one that could be used. Thanks for the help (Edit) Some of ...