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

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89 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 ...
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190 views

How to learn molecular biology through pubmed research articles?

Instead of using a textbook, is there an alternative curriculum, that simply lists a set of pubmed research articles for each topic covered in a typical undergrad molecular biology course? I am ...
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683 views

Why do neurones use chemical signalling at synaptic junctions?

Problem. When a neurone fires, it sends an electrical signal that jumps down the axon via the nodes of Ranvier very rapidly. At a synaptic junction, chemical brownian diffusion signalling with ...
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2answers
102 views

What's a protein pulldown assay?

I'm reading a paper and the authors mention a "protein pulldown" assay. I've never done this before, and googling doesn't bring up much. Could I get a rundown of the basic theory behind it? Also ...
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65 views

Nomenclature of genes and proteins

With respect to this paper: Identification of Host Proteins Required for HIV Infection Through a Functional Genomic Screen In the abstract, I found names such as Rab6 and Vps35 and TNPO3. So Rab6 ...
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1answer
104 views

What do “e” “-” “C” and “E” mean in this output?

I have given an input of this protein sequence: MEPVDPRLEPWKHPGSQPKTACTTCYCKKCCFHCQVCFTTKALGISYGRKKRRQRRRPPQGSQTHQVSLSKQPTSQPRGDPTGPKE from this website along ...
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2k views

What is DNA binding domain? It is not clear what the domain means

I am confused about the term DNA binding domain. Does it mean that there are some parts of the DNA that tends to coil up? Does it happen because some proteins tend to stick around that area? Also it ...
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56 views

Self pairing in DNA

I know that ssRNA molecule can fold over itself (e.g. in t-RNA). Can DNA do the same? Is there any example of this in nature? Why is this phenomenon more common in RNA than in DNA?
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81 views

Can I use PCR buffer instead of cDNA synthesis buffer?

I am using Fermentase First strand cDNA synthesis kit but its buffer is over. I need to work today but I have not access to any sorce currently. I have PCR buffer in the lab. Can I use PCR buffer ...
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2answers
90 views

How common is bacterial mediated transformation? In plants? In animal cells?

The most common method to transform plants is by soaking plant tissue in cultures of agrobacteria (this is not their current classification) which transfer DNA into the plants. Is lateral gene ...
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88 views

What type of flask should I use to culture NTERA2 embryonic cancer stem cells?

I'm just starting my MSc research and I am in the process of making a list of equipments/consumables to order. Is there a specific flask in which I can culture NTERA2 (NTERA2/D1) cell line?
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71 views

Western Blot: Fischer ECL substrate 2:1 instead of 1:1?

i recently developed a b-actin-ab-incubated PVDF-WB-Membrane with the Thermo Scientific Pierce ECL Kit. According to the manufacterers orders i mixed Reagent 1 and Reagent 2 1:1. But unfortunately i ...
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278 views

Can replication occur if DNA is methylated?

Can a methylated strand of DNA be replicated without removing methylation? Does it make any difference if the strand is methylated or not (during replication)?
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86 views

How does the DNA know which chain has error in repairing?

As we know, the DNA has more stability than RNA, if one chain has broken or accidentally distorted, it can be repaired by the other one. Suppose there is a segment AGTC, its peer is GACT. Now its ...
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237 views

Do Yeast Insertion constructs revert?

If I insert a new gene with a yeast integrating plasmid and select with a drop out culture once, can I assume that the newly integrated gene will stay in the strain without putting selective pressure ...
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42 views

Are restriction enzymes active at −20 °C?

I have digested my DNA with NotI enzyme and put it in the −20 °C freezer without heat inactivating it. Can restriction enzymes work at −20 °C? Should I expect STAR activity?
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133 views

How does temperature influence the rate of protein degradation?

For computer modeling purposes, I am looking for some referenced quantitative measurements of the effect(s) of temperature on biochemical reactions. Question In particular, my question is: How does ...
3
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159 views

What is a protective epitope?

What is a protective epitope? An epitope is basically a part of antigen. So does it mean that when the epitope combines with an antibody, it helps in the functioning of the antibody instead of going ...
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92 views

Consumption of NAD+ in glycolysis

Out of 10 steps in glycolysis, only one reaction- Glyceraldehyde 3-phosphate (G3P) to 1,3-bisphosphoglycerate (PGP), uses NAD+ and thereby producing NADH. Furthermore, this very step is solely ...
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743 views

Difference between “transcriptional activity” and “RNA expression”

I am working with a network object where the nodes are different events in molecular biology. Specifically; Catalytic activity of X, RNA expression of X, GTP-bound activity of X, Kinase activity of ...
3
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206 views

Does sample buffer require EDTA for protein separation on SDS PAGE?

In sample buffer preparation we add EDTA, but if SDS-PAGE is for protein then is it necessary to add EDTA in sample buffer? What is role of EDTA in sample buffer for protein separation for SDS-PAGE.
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66 views

Why aren't introns found on the ends of pre-RNA?

We recently learned in genetics class that exons always cap the ends of nascent RNA. I have been trying to figure out the reason why introns can't instead be found on the ends instead of exons. The ...
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48 views

Propensity Score for amino acid

What is the meaning of propensity score of amino acid? How is it calculated? (I have not studied biology since last 8 years and now I am going through it because I need it for my research. So if ...
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1answer
83 views

Efficiency of plasmid DNA isolation from frozen E. coli cell cultures

Has anyone isolated plasmid DNA from frozen (at -20degrees) E. coli cell cultures (not pellets)? Has that worked and if so, with what yields? What would be the quality of the isolated plasmid DNA if ...
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38 views

Heterochromatin production limitations

Currently playing with some ideas for a project and needed some guidance. I am wondering, both in Drosophila melanogaster and in general, is the amount of heterochromatin a cell/nucleus can produce ...
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180 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?
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138 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 ...
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342 views

Why does methylation not occur in viral DNA?

Why does methylation not occur in viral DNA? Can viral DNA undergo the process of methylation? If not then why does this process does not occur in viruses?
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44 views

How do you express and detect GLP-1 receptors?

I am currently working with a peptide which is an analogue for glp-1, but during invitro studies am not able to detect for the presence of GLP1- receptors. The cell line used is Min-6. How do I detect ...
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3answers
1k views

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 ...
3
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1answer
180 views

What molecular processes are involved in pseudopodial extension?

I am curious as to the processes and mechanisms involved in the extension of pseudopodia in amoeba. How does the cell know and control the direction and extent of pseudopodia formation at a molecular ...
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199 views

How do I create a probe for in situ hybridization?

I tried to make the probe several times but it failed again and again. It usually turns out that the probe after hydrolysis is very very short (maybe around 50nt). I did not check the RNA before ...
3
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1answer
66 views

How is the type of genetic manipulation determined in CRISPR-Cas9?

I've been reading up a bit on the CRISPR-Cas9 system for gene manipulation. From what I read, it introduces double-strand breaks at specific points determined by the choice of sgRNA. But how do you ...
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21 views

Authority on Microbiological Definitions

Is there an authority on definitions for molecular microbiology concepts, like an IUPAC book for chemical definitions? The particular definition I am debating is chromatin. Some say it encompasses ...
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63 views

PSI-BLAST website algorithm parameters

http://blast.ncbi.nlm.nih.gov/Blast.cgi In this website, when I want to apply the psi-blast algorithm on a sequence, under the section of algorithm parameters , what does PSI-BLAST threshold mean? ...
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45 views

SEREX serological analysis of cDNA expression library

What is Serological Analysis of cDNA expression library? I went through this article:http://cancerimmunity.org/serex/introduction/ but could not really make out. Can someone please explain this to me ...
3
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1answer
959 views

How does blue white screening work in selecting E coli that have taken up a plasmid vector?

The plasmid vector I am referring to is pCR 2.1 - TOPO. I added the vector to the E coli and plated them up onto LB+amp+X-gal plate, then incubated. After incubation the plates had two types of ...
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78 views

Why not use Cu(OH)2 as a dye for protein electrophoresis?

As I know, $Cu(OH)_2$ $+$ Protein $\rightarrow$ Purple. So why not use $Cu(OH)_2$ as dye in protein electrophoresis?
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746 views

Just how light-sensitive is ethidium bromide?

One lab I was in was paranoid about keeping it in a foil-wrapped conical tube; my current lab leaves it out on the bench (and it works fine for staining gels). It's the same company/concentration in ...
3
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1answer
659 views

Optogenetics - How do microbial opsins work?

I'm just introduced to the optogenetics method and am having some trouble grasping the genetics (of the optogenteics) part of things. So we have Retinal and Opsin that form Rhodopsin molecule that ...
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167 views

What are centromeres *really*?

I've gathered that a centromere is a a region* where the DNA is bundles up even tighter (around protein different to Histone) and chromatids are 'joined'. However I'm still mostly in the dark ...
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115 views

205 nm UV-Vis readings

Typically we determine the concentration of proteins using a 280 nm reading. However, it is reasonable to use 205 nm. I was curious about the effectiveness of this method.
3
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1answer
43 views

How can (or did) Deinococcus radiodurans continue to evolve after developing resistance to mutation?

Deinococcus radiodurans has a remarkable ability to resist damage to its DNA due to radiation, dehydration or (to my knowledge) any other source. It keeps multiple copies of its genome and has a ...
3
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1answer
134 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 ...
3
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1answer
127 views

Real-time PCR delay in Cq due to insertion SNP in primer

I am collecting evidence, even anecdotal, how does single nucleotide deletion or insertion in primer region affect the outcome of real-time PCR. I am most interested in how much there is a delay in ...
3
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1answer
82 views

Transposons and the net amount of DNA

The retrotransposons and certain DNA-transposons, are "jumping" sequences which may be incorporated elsewhere in the genomic DNA of an organism, through varying mechanisms. This insertion is almost ...
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962 views

What is the exact principle of capillary isotachophoresis?

I know it's a type of capillary electrophoresis, but I don't get how does the separation happen exactly.
3
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1k 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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547 views

Why re-label the strand ends in 3' DNA labelling?

I have a problem with a molecular biology question; I don’t understand how DNA 3’ labelling works. I took a diagram from my lesson and tried to understand with it; this is what I understood. If I’m ...
3
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1answer
119 views

High protein turnover rate and protease inhibitors?

I work with mice, and I want to see what happens to some specific proteins in the mouse brain after IL-1b injection (intracerebroventricular). I have a problem: when I measure the mRNA and protein ...