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

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1answer
2k views

Difference in length of Okazaki fragments

The length of Okazaki fragments in the lagging strand is about 100-200 nucleotides in eukaryotes and about 1000-2000 nucleotides in prokaryotes. What (molecular mechanism, enzyme type ) ...
1
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1answer
51 views

difference between ischemia and oxygen-glucose deprived medium

Ischemia is roughly defined as insufficient blood flow to a specific region of the body and in the literature it is generally considered as causing oxygen and glucose deprivation in the tissue and ...
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2answers
5k views
4
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1answer
279 views

Why Isolated, recombinant plasmid DNA without any restriction is often detected in agarose gel electrophoresis as three DNA bands?

I don't understand why three bands are found without any restriction digest. Please answer me as soon as possible. Thank you
1
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1answer
289 views

What is Pan for in pan-caspase?

A simple question (I could not find it on internet): What is Pan for in pan-caspase? Is it any different from the term 'caspase' ?
2
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2answers
183 views

Single stranded DNA in gel electrophoresis

From http://www.nfstc.org/pdi/Subject05/pdi_s05_m01_01.htm : ... The separation medium contains a denaturant in order that the electrophoresis is conducted on single-stranded DNA fragments. ...
4
votes
1answer
96 views

Are there any organisms that lack ATP synthase?

ATP synthase is used by cells to synthesise ATP from ADP using energy from a proton gradient. Depending on which sites I look at, this is either a universal feature of living cells, or it's "almost ...
4
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2answers
103 views

A photosynthesizing mouse?

N. Shubin's Your Inner Fish makes the point several times that there is a lot of functional similarity between some seemingly remote gene cousins. If that needed reinforcing we have the spider-goat, ...
0
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1answer
27 views

Property of E.coli harboring F element

From Genetics by Ursula Goodenough E.coli harboring an F element are endowed with a number of phenotypic traits : 1.They are sensitive to infection by ssRNA phages and certain ssDNA phages. ...
3
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1answer
93 views

What is “bacto” peptone?

Standard recipes for yeast medium often include "bacto-peptone". Is this the same as bacteriological peptone? Is there an authoritative source that spells it out?
2
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1answer
61 views

How was Restriction Site of EcoRI sequenced?

The sequence of restriction site of EcoRI - GAATTC was identified in the early 1970s, before Sanger Sequencing was invented.(1977) How was the restriction site of EcoRI sequenced ?
2
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6answers
189 views

Sequence analysis software suites

I have used DNAStar laser gene and VectorNTI in the past for cloning, primer design, sequence alignments, etc but no longer have access to these. Are there any comparable replacement suites or what ...
1
vote
1answer
75 views

What is a phospho-protein binding domain?

Is this just a domain that binds proteins that have been phosphorylated? And it mediates signalling between an activated/phosphorylated protein? How is this significant with BRCA1?
0
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0answers
65 views

PQR files make from pdb2pqr are different to GROMACS [closed]

I have a pdb file and I would like to make a pqr one. In GROMACS, I use editconf -mead to produce pqr, with topol.top taken from pdb2gmx or use it to produce pdb file, then use pdb2pqr. Which one is ...
2
votes
1answer
39 views

Trimming of tRNA precursors

From Molecular Biology of the Cell (4th edition) by Bruce Alberts et al. (Chp 6, Pg 338) : Both bacterial and eucaryotic tRNAs are typically synthesized as larger precursor tRNAs, and these are ...
0
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0answers
30 views

What is the suitable terminology to describe this study approach?

I need to know the correct term(s) which are usually used in the parlance of both biology and bioinformatics for this study approach: About 11 transcripts were investigated using qPCR for a number of ...
1
vote
1answer
91 views

A question related to qPCR analysis

Here is the thing. I am using a method, called TU-Tagging, to isolate cell type specific RNA. You can find more about the method here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2783170/ To explain ...
3
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1answer
122 views

Do macrophages engulf mtDNA?

Let us assume that in a human body, a mitochondrial DNA is released to extracellular environment. We know that mtDNA inheritance is solely matrilineal. So the question is, If your mitochondrial DNA ...
5
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2answers
288 views

Signaling through G protein Coupled Receptors?

There are two different cell lines but we do not know that these cell lines have Gs or Gi proteins, associated with their G-protein coupled receptors. If we wants to know about this. Can we design a ...
4
votes
1answer
169 views

how is the plasma membrane repaired after endocytosis?

When the vesicle is swallowed of course the lipid layer internalizes. My question is how will the top segment of membrane will bind back together when that vesicle took the membrane with it inside ...
2
votes
1answer
50 views

H O N C alternatives for organic life?

Most organic structures built from hydrogen, oxygen, nitrogen and carbon. They are represent 1-,2-,3-,4- bond relations (chemical valence) which allow to build variety of chain structures. Are there ...
2
votes
1answer
507 views

What's the physical meaning of Svedberg unit?

Sedimentation coefficients, using a centrifuge, are expressed using Svedberg unit (symbol S, sometimes Sv). Wikipedia states that $S = 10^{-13}$ sec but I also saw in a book that actually $S = ...
1
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0answers
35 views

Study case of the inheritance system of Oenothera

I've been told some interesting facts about oenothera. Apparently in this species some lineages have been through some translocations and in results to these translocations and in consequence, some ...
2
votes
2answers
59 views

In genome research, what is the problem in Mapping that may be caused by reads being too short?

In the following scenario: You were given short sequence reads of plant RNA obtained from a next-generation sequencing machine (fragments of 20–30 nucleotides in length). You attempt to map them back ...
4
votes
2answers
102 views

Detecting food fraud

There's undoubtedly more than one way to do this, but if a DIY biologist were to attempt to detect food fraud (e.g. as done by students from Stanford University and Trinity School, Manhattan with ...
3
votes
1answer
116 views

Biological meaning/interpretation of clustering coefficience

I have been looking for some time to find an answer to the following question. I would be grateful for any help/advice or directions. I work very frequently with large number of proteins and assess ...
4
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2answers
1k views

What is the difference between transformation and transfection?

What is the difference between transformation and transfection? How do both of these methods work?
2
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2answers
119 views

Image analysis of GFP-tagged protein localization bursts

I'm reading an article (full text here) that analyze the dynamics of localization of a GFP-tagged transcription factor (Crz1) over the time at the single-cell level, by taking movies in a fluorescent ...
2
votes
1answer
50 views

What are the Gateway clonase enzymes?

The Gateway cloning system utilizes what Life Technologies refers to as "Clonase enzyme mix" to catalyze the BP and LR reactions. What is in this enzyme mix? Is there a sequence for them?
3
votes
2answers
129 views

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 ...
2
votes
2answers
85 views

Modern alternatives of DNA footprinting

Since DNA footprinting is an old method I thought there may be some more recent and effective methods to identify a DNA sequence, do you know any of them?
4
votes
1answer
111 views

Topology of closed circular DNA

Why are covalently closed circular plasmid DNAs naturally found in an underwound state ? Is it because this makes it easier for the DNA replication machinery to access and unwind DNA ? Or is it ...
2
votes
3answers
97 views

Why doesn't the cytosol dissolve the polar structures?

we know that cytoplasm of cells are filled with water molecules and other hydrophilic molecules so my question is why the water of cytosol doesn't dissolve the ionic part of the lipid bilayer or why ...
2
votes
1answer
77 views

Role of isopropanol in plasmid isolation

In plasmid isolation, isopropanol is used to renature only the plasmid macromolecules after we precipitate all macromolecules(DNA, RNA, plasmids) using sodium acetate solution. How does it do that? ...
2
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0answers
204 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, ...
3
votes
2answers
249 views

How can CI repressor both activate and repress $P_{RM}$ promoter found in $\lambda$ phage?

I'm reading a paper where the authors constructed a toggle switch that uses bidirectional $P_R/P_{RM}$ promoter found in the $\lambda$ phage. There are 3 binding sites - $O_R1$, $O_R2$, $O_R3$ - ...
1
vote
1answer
59 views

Missing 4$H_2O$s (per glucose) in Cellular Respiration… Where can they be?

I having trouble understanding the equation of the cellular respiration. The thing that bothers me is the number of $H_2O$ molecules. Generally, cellular respiration is written thus : $C_6H_{12}O_6 + ...
1
vote
1answer
124 views

Troubleshooting for Agarose Gel Electrophoresis

SI ran my 2% agarose gel on constant voltage (100 V). For a few times it worked at CV but, after a week or so the machine would automatically switch to constant current by itself. And this only ...
11
votes
1answer
2k views

How does translational coupling work in prokaryotes?

Today I heard about a phenomenon called "translational coupling", where the translation of one protein influences the translation of another protein. The messenger RNA levels don't seem influenced. ...
4
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2answers
127 views

Is AT or GC content important in electrophoresis?

Will it make a difference in running speed if we run samples of same no of bases but different AT - GC content ?
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0answers
86 views

Which mutagen is responsible for pancreatic cancer [closed]

Which mutagen, aflatoxin or acridine orange (an intercalating dye) would most likely lead to an increased incidence of pancreatic cancer. Why?
2
votes
1answer
60 views

Do you have experience with PacBio?

I prepare a experiment and I found $PacBio SMRT$ as the great way to sequence my PCR products. I find the cost: library preparation 655 dollars + sequencing 435 dollars. It seems very low. Do you have ...
3
votes
1answer
81 views

How to measure quality and quantity of DNA?

I would like to mesure DNA. I quantify the concentration with Qubit fluorometer, but I would like to know also quality of DNA. I try BioAnalyzer (Agilent),but without success. Bioanalyzer measure DNA ...
2
votes
1answer
75 views

Substitute 25mM dNTPs mix with 10mM dNTPs

I need to make a solution of multiple compounds, one of them is dNTPs. The recipe calls for 20 μl 25 mM dNTPs in a 1250 μL master mix. Unfortunately I do not have it available at that concentration, ...
1
vote
2answers
67 views

Functioning of EDTA

I know that EDTA chelates metal ions. It weakens bacterial cell wall and inactivates the DNases. What is the reason why it can do so ? I guess it can inactivate DNases by altering the ...
2
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1answer
33 views

Transport of mammalian insulin in vivo

What is the mechanism for transport of insulin in mammalian cells?
10
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2answers
5k views

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 ...
2
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0answers
118 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, ...
1
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1answer
62 views

Why bacteria produce light?

After seeing this video I am curious to know why the free living bacteria produce light. What advantage will they have ? Or is it just an "unintentional" result of one of their pathways ?
14
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6answers
1k views

Online Molecular and Cellular Biology Video Lectures?

I am looking for video lectures to go through to guide my reading in intro molecular and cellular biology. I've had intro bio and I study evolutionary theory, but my molecule- and cell-level knowledge ...