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

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113 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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0answers
38k views

Does CPH4 exists? [closed]

What is the purpose of CPH-4? Is it well represented in the movie Lucy?
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4answers
100 views

determine longest poly-purine tract

how to determine/ find the longest poly-purine tract in any genome and this needs to be on the E. coli genome . is it to figure out the polypurine tract and then figure out the longest chain ? or is ...
3
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2answers
331 views

How are DNA segments selected in PCR?

I understand that in PCR we're able to amplify only selected portions of the DNA... however despite reading it from multiple sources, I cannot figure out how this selection actually takes place. I ...
2
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1answer
272 views

Why does the pET- expression vector contain a LacI gene additionally to the one in the genome?

The pET plasmid is used for protein expression with T7 promotor in expression strains, such as E.coli BL21(DE3) It contains a lacI gene which codes for the lac repressor protein, a protein of ...
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1answer
101 views

No digested product bands, but markers are visible. What could be the reasons?

I had to digest my insert containing plasmid and another vector into which my insert has to be ligated, each with BamHI and NotI. Upon digestion, I ran the gel to check for results. The digestion ...
3
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1answer
44 views

Cross section of actin network in neurites

for a simulation I am developing I would like to know how the actin network in neurites is distributed. Is actin confined to the periphery or is the whole neurite shaft containing actin with a rather ...
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1answer
216 views

Has anyone used Crispr/Cas to induce a knock-in in MEF cells?

Does anyone have experience with the crispr/cas9 platform performed on MEF? Or does anyone recall any relevent articles? Thanks
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154 views

High frequency human genetic oscillators?

The most well studied genetic oscillators in human genomes are involved in regulating the circadian clock (which operates on an approximately 24-hour cycle) and cell cycle activity (with single cycles ...
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85 views

What are some atypical examples of positive transcriptional cooperativity?

Cooperativity in gene expression is an important feature of many regulatory networks. Described using the Hill function, the most common example is a transcription factor (TF) that when bound to its ...
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1answer
627 views

RNeasy Mini Kit low 260/230 ratio — can I purify this RNA for further use?

I used Qiagen's RNeasy Mini Kit to isolate RNA from 5*10^5 C28/I2 (immortalized human chondrocytes). However, my yield is low (~25 ng/ul), but my 260/280 ratio is great (~2.3), and my 260/230 ratio is ...
3
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1answer
107 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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39 views

Assembling DNA fragments with ~10kb overlap in vitro

Let's say I have two fragments of bacterial DNA (~50kb in length each) that overlap on the ends by roughly ~10kb; the overlap sequences are unknown. I would like to assemble these into longer ...
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15 views

border zone of the infarcted heart

I did myocardial infarction experiments on mice and I am a newbie in this area. I need to isolate RNA and protein from the remote and the border zone. Where should I cut the heart so i can separate ...
4
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1answer
65 views
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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 ...
2
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1answer
41 views

Kinesin-5 / cytoplasmic dynein spatial density distribution in neurons

Is there some way to experimentally determine the density distribution of Kinesin and Dynein in a Neuron? Fluorescence labeling would be impossible(?) as GFP markers would probably alter the motor ...
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3answers
50 views

FRET only works for interactions between 1nm to 20nm.

FRET only works for interactions between 1nm to 20nm. How can you be sure that the interaction that you want to study isn't less than 1 nm/greater than 20nm apart?
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3answers
118 views

What equipment would one use to modify a virus? [closed]

Would anyone be so kind as to give me a few examples of the equipment involved when modifying a virus? Otherwise my novel may end up reading Eva entered the lab and modified a virus. Not much back ...
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4answers
136 views

Theoretically, what technique would one use to modify a virus so that it only affected a subset of the population?

I'm writing a novel and i would like to know some of the equipment and techniques involved with modifying a virus. Is it feasible for a virus to be engineered to only affect certain people? It ...
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1answer
437 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
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1answer
58 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 ...
4
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1answer
89 views

Do mitochondria use ATP in order make another ATP from glucose?

Do mitochondria use ATP in order make another ATP from glucose, or does it use another source of energy to convert glucose to ATP?
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2answers
822 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' ?
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2answers
301 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. ...
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1answer
567 views

How tolerant are ants to cold?

There was a trail of what are commonly known as sugar ants (small, brown, hyperactive) in my kitchen. Three of them walked onto an ice tray placed in their path. They only walked a short distance on ...
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1answer
1k views

What is the definition of a stringent/relaxed plasmid?

I have found a publication which proposes some definitions, including a definition for strict and relaxed replication. The definitions are: Relaxed control of plasmid replication. Relaxed control ...
4
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1answer
193 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 ...
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2answers
113 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, ...
3
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1answer
254 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
76 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 ?
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1answer
55 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 ...
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39 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 ...
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1answer
113 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 ...
4
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1answer
246 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
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1answer
1k 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 = ...
2
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1answer
59 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 ...
3
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1answer
149 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 ...
2
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2answers
63 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
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2answers
302 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 ...
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2answers
111 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 ...
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0answers
36 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 ...
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2answers
3k 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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1answer
88 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?
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2answers
140 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 ...
4
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1answer
119 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 ...
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2answers
102 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?
3
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1answer
138 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 ...
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3answers
97 views

Hebbian theory “fire together” clarification

Donald Hebb states it as follows: "Let us assume that the persistence or repetition of a reverberatory activity (or "trace") tends to induce lasting cellular changes that add to its stability.… ...
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1answer
3k views

How does a TOPflash/FOPflash assay work to detect beta-catenin protein expression?

I am reading an article (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3596711/) wherein a TOPflash/FOPflash assay is used to detect beta-catenin protein levels in a COS-7 cell line. I can't find a good ...