8
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A biological system to measure time
There are lots of biological clocks, or clocks made of biological components. The circadian clock is an important, though complicated, example. There are excellent engineered clocks that form some of ...
7
votes
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Why is glycerol supplied/used as 87% solution?
Typically, a glycerol stock will have a final concentration of 10-20% of glycerol. Glycerol is highly viscous. Pipetting higher concentrations of glycerol is difficult (especially for smaller volumes)....
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6
votes
Tumour cell injection into a mice
You should not be asking random people on the internet about this. Talk to your lab safety people. Get detailed instructions on handling requirements. As for the hood, again, do not ask here, ask your ...
- 14.2k
6
votes
Is it safe to work with HeLa cells?
Most guidelines for HeLa (and most cells of human origin) say they should be kept at a BSL2 level. For example, from a 2007 publication in Applied Biosafety:
Work with cell cultures from human or ...
- 14.2k
5
votes
Decreasing signals in assay measurements
Freeze-thaw cycles are often suspected of causing degradation in organic molecules 1,2. My first guess would be that your fluorophore is breaking down due to those repeated cycles. Alternatively, you ...
- 5,577
5
votes
Appropriate cell lines to study depression
tl;dr there is no 'depression' cell line. Cell lines would be suited for studying pharmacology, cellular or molecular mechanisms, none of which are depression. Depression also has no good correlates ...
- 6,192
4
votes
Accepted
Does a specific blood group enhance the Plasmodium growth?
It is a well documented observation that Plasmodium (vivax and knowlesi) infection is dependent on the Duffy blood groups [1].
Individuals lacking the Duffy antigens (Fya and Fyb) have lower ...
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4
votes
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Do bacteria grow on pure dry glucose?
Bacteria or other microorganisms cannot really grow on anhydrous (totally dry) glucose because they need water.
However, they can remain there and cause contamination. Even if you haven't actually ...
- 35.2k
4
votes
Accepted
Is there a difference between "cell line" and "cell strain"?
"Strain", in general, is usually used for whole organisms (whether they are unicellular or multicellular). For example, there are mouse strains.
"Cell line", on the other hand, is a very specific ...
- 35.2k
4
votes
Trypsin and Cell Surface Receptors
Yes. Trypsin cleaves proteins and can do so quite indiscriminately if left on for very long. Trypsin is primarily used to cleave the proteins that cells use to adhere to each other and the plate in ...
- 1,309
4
votes
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Mold identification
I initially figured it was condensation from the agar. But it is not on your lid and you said you suspected humidity was low.
I found this here http://www.gettyimages.ca/detail/photo/mold-...
- 2,964
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 ...
- 5,568
4
votes
What is the meaning of harboring cryptic in below sentence?
Harbouring, using harbour as a verb and in this meaning containing/hiding (see 3rd and 4th definitions at Harbour)
Cryptic = hidden/difficult to find - this is how the word is often used in biology, ...
- 11.2k
3
votes
Accepted
Mass production of bacteria
The fed batch culture is a means of bacterial production that is used in industrial setups. Nutrients are fed into the chamber with controlled ideal conditions for growth of a particular species of ...
- 557
3
votes
How far is stem cell research from being to generate a new organ?
Sperm can already be generated using stem cells http://blogs.discovermagazine.com/d-brief/2016/02/25/scientists-grow-working-sperm-from-stem-cells/#.V-UADBV94o8
Also, heart, liver and kidney cells as ...
- 3,098
3
votes
Accepted
Did the Hela cells leave John Hopkins
Cultures of HeLa cells are used in many labs around the world, and were widely shared from very early on. From the Wiki:
In the spring of 1953, a cell culture factory was established at
Tuskegee ...
- 3,304
3
votes
What kind of detergent should I use in cell culture laboratory for cleaning purposes?
I agree with Mike, but would like to add that if you are trying to do protein expression for purification, some detergents contain polyethylene glycol (PEG), which will readily bind to many proteins, ...
- 301
3
votes
What kind of detergent should I use in cell culture laboratory for cleaning purposes?
I can't tell if you're asking about glassware or work surfaces (hoods, benches etc), but...
We use regular old dawn dish soap in my lab because what's more important than the soap you use to wash you'...
- 31
3
votes
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Can you replace glucose with glycerol in cell media?
In most cases, it's not a good idea to replace glucose with glycerol in animal cell media. Animals do possess the ability to metabolize glycerol, via a pathway starting with the enzyme glycerol kinase....
- 254
3
votes
Is it possible to grow E. coli K12 with algal amino acids as the sole carbon source?
E.coli can do that and in fact does this a lot in a commonly used bacterial medium: The popular LB Medium. This is composed of three components:
Tryptone, a peptide mix made by digesting milk casein ...
- 51.5k
3
votes
Accepted
Soft Agar Substitute
The good news is: You don't need any agar in your plating media, since the bacteria grow on the surface anyway and the plate can take up some additional moisture from your plating media.
What I ...
- 51.5k
3
votes
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What are mouse LS cells?
Not an easy question, but I got some references about it.
Mouse LS cells are Fibroblasts growing in suspension culture, the paper in reference 1 has this paragraph in its Materials and Methods section:...
- 51.5k
3
votes
Why does vacuum sealing of foods prevent spoilage from anaerobic bacteria?
I do not understand why anaerobic bacteria, that don't require and cannot survive in air, do not proliferate and thrive in the vacuum sealed food containers
They do. Vacuum sealing can prevent ...
- 43.9k
3
votes
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Where can I find a video of human cells reacting to cold water vs warm?
You can't see these changes easily under a microscope. It is a challenge to add heat or cold to cells on a microscope in a manner that you might see, unless you have the right equipment.
You might ...
- 11.2k
2
votes
Confluency or confluence, which term is correct to describe the % area covered by cells?
Searching Google Scholar for cell confluence returns 239000 hits, while searching for cell confluency returns 75000 hits.
A look at the context in which they are used supports my gut feel, which is ...
- 9,432
2
votes
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Formula for number of divisions required to form x number of cells (Mitosis and Meiosis)
For a male, one primary spermatocyte produces two secondary spermatocytes through meiosis I, which in turn produce two spermatids each through meiosis II. So one primary spermatocyte produces four ...
- 268
2
votes
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How to induce a steady increase in cyctoplasmic [Ca2+] in HEK293T cells? And is there any simple marker/method to confirm it?
As far as I know, microscopy (be it with dyes like fluor or with genome-encoded calcium indicators) is really your only good bet, especially for getting quantitative sensitivity, which I think is what ...
2
votes
Accepted
Respiration of an animal cell media
Supply of cells growing in adherent culture is unproblematic, as long as you don't fill too much media in the petri dish/cell culture flask.
Oxygen supply here work by diffusion which is getting more ...
- 51.5k
2
votes
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Purpose of dilution streaking or streak purification
The purpose of this technique is to dilute the bacterial cells so much that you get single cells, as can be seen on the image of the plate. You can then pick the colonies grown from these single cells,...
- 51.5k
2
votes
Pipetting damage to cells
I know this is a two-year-old thread, but I though I would post this anyway in case someone else is searching for this answer like I was tonight. This article cited below doesn't discuss pipette tips ...
- 21
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