5 votes
Accepted

Did early 20th century researchers state why they used E. coli as a model organism?

Historical Fallacies implicit in the Question “…why a researcher chose to use E. coli as a model organism.” Researchers did not work with E. coli because they regarded it as a “model ...
David's user avatar
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4 votes
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Why do coliform bacteria smell so bad?

E. coli and other bacteria metabolize tryptophan into odoriferous skatole and other indole compounds. If you're culturing these organisms in medium that contains tryptophan, that may be what you're ...
Alex Reynolds's user avatar
4 votes

Did early 20th century researchers state why they used E. coli as a model organism?

Very interesting question. Did early 20th century researchers state why they used E. coli as a model organism? In short: No (at least in the 1920ies). For instance: Werkman 1927: Vitamin Effects ...
tsttst's user avatar
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4 votes
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What is the mass of an E.coli cell?

Its simple: Mass = Density * Volume = 10^3 (Kg/m3) * (10^-18 m3) = 10^-15 Kg which is equal to 10^-12 gram or 1pico gram
Failed Scientist's user avatar
4 votes

Recombination frequency as a function of genomic location in E coli?

A recombination map of the E. coli genome was recently published (several years after question was asked).
Maximilian Press's user avatar
3 votes

Mutations in a Petri dish overnight

We can calculate the number of base pair copy errors in a Petri dish per hour by multiplying the number of base pairs (B), the copy error rate (P), the number of divisions in an hour (D), and the ...
Daniel Darabos's user avatar
3 votes

Why do E.coli form parallel clusters?

Cell division happens by division at the middle of the rod, so the result is two daughter cells that are at nearly the same angle. Over time in the absence of agitation moving cells around, this will ...
Maximilian Press's user avatar
3 votes

Plotting metabolic networks?

This is an old question, but Escher is a web app that has been developed that now enables the drawing of these maps using a web tool. Further customization (like reaction colors) could be manually ...
achilles's user avatar
2 votes
Accepted

Unwanted E. coli product in plasmid product

The root cause turned out to be a lying spec. Using a different one, it was revealed that there was next to no template DNA in the initial amplification. No DNA, no good plasmids.
Jess The Witch's user avatar
2 votes
Accepted

Why do two different E. coli reference genomes have different lengths?

U00096.2 is an updated version of U00096.1; you should preferably use the former for your analysis. In fact, even U00096.2 has been updated. The latest version is U00096.3. In general, the number ...
WYSIWYG's user avatar
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2 votes
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Are there ways to genetically increase mutation rate of E.coli?

Mutations are caused by the insertion of the wrong bases during replication, or by chemical changes to bases, either by chemical agents or by radiation. The rate of mutations could be increased by ...
VonBeche's user avatar
  • 1,473
2 votes

Why pellet and resuspend E. coli for plasmid prep

The reason this centrifugation/resuspension step is done has a simple reason: It concentrates the bacteria in a much smaller volume which is much easier to handle afterwards. For a maxiprep you ...
Chris's user avatar
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1 vote
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Correlation of Meselson and Stahl with “multifork” replication in E.coli

It is sometimes considered that the result was an artifact for a reason similar to that which you mention. However, it happened to be correct in its conceptual outcome, and was not rejected by ...
Maximilian Press's user avatar
1 vote

Why do E.coli form parallel clusters?

Bacterial cells prefer to attach with each other in parallel orientation so that they have maximum surface of contact and could form biofilm clusters. Both physical factors (like Brownian motion, ...
Twinkle Sheen's user avatar
1 vote

How to estimate mRNA counts from Relative Promoter Units (RPU) or RNAP per second (PoPS) in E. coli?

I could not find any paper that discusses these issues. So this answer is just based on my guess. From the this page: Transcription rate is generally a parameter associated with a particular ...
WYSIWYG's user avatar
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1 vote

How can I improve efficiency of Ecoli transformation?

The plasmid is quite big which might explain why it is difficult to transform bacteria (is it a lentiviral vector?). If you could give additional details you might have a chance to have improved ...
Dr. H. Lecter's user avatar
1 vote

Plasmid specific DNA degradation

traditional method to remove a plasmid from E. Coli is to grow the cells with Etidium bromide. http://vlab.amrita.edu/?sub=3&brch=186&sim=1097&cnt=1
JayCkat's user avatar
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1 vote

Why do two different E. coli reference genomes have different lengths?

As WYSIWYG answered, they are updated versions. The difference in length is mainly because that later versions are sequenced / aligned with better equipement and techniques, providing results that ...
Dart Feld's user avatar
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1 vote

E. Coli metabolization of paracetamol

Sorry that my answer is not a real answer, but this would be a good starting point for some more science. Several of the questions you might ask and could answer (with some more experiments): Does ...
VonBeche's user avatar
  • 1,473
1 vote

Dissolving cell pellet after sonication

Follow the instructions that came with your column for cleaning. The resin will probably be fine, but you'll need to thoroughly clean the column. My GE columns recommend washes of: 20% EtOH 30% ...
Joe Healey's user avatar
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1 vote
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What nutrients are best suited for growing E.Coli

Optimal is a funny thing; it depends upon what you want. The purpose of the bacteria, is probably the most important aspect when considering the nutrients. There are many recipes capable of growing E. ...
Ben Welborn's user avatar
1 vote

How does a bacterium age without cell division?

First of all, the growth of a bacterium is associated with an increase in cell biomass.So if a bacterium is restricted from replicating it does not grow. Coming to your later parts of the questions ...
Akhil's user avatar
  • 11
1 vote

Codon tables and the wobble hypothesis

This is a good question as, although in higher eukaroyotes codon usage does not necessarily correlate with translational efficiency, it does to a large extent in Escherichia coli (see e.g. Boël et al.,...
David's user avatar
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1 vote

Why and how is DNA synthesis so much faster then RNA synthesis in bacteria?

I wouldn't call them hypotheses, but the question is intriguing, and, as it seems to be ignored in the literature, I'll make a couple of suggestions. Perhaps it has something to do with recognition ...
David's user avatar
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1 vote

Whence fecal E. coli (et al.) if swallowing it is dangerous?

There are many varieties of E. coli, with differences in their chromosomal DNA, different plasmids (independent loops of DNA that replicate autonomously inside the host cell and can be transferred ...
S. McGrew's user avatar
  • 737

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