All Questions

13
votes
1answer
192 views

How straightforward is in vitro compartmentalization?

in vitro compartmentalization (IVC) is one of those technologies that everyone knows about, talks about, but never actual does due to the rather technical difficulties in setting the system up. I was ...
11
votes
2answers
172 views

protocol for pulldown of DNA breakpoints?

Is there any method to do pulldown enrichment of DNA breakpoints from a cell? I have found this paper reporting a method to enrich for the DNA single-strand breakpoints from meiotic recombination ...
3
votes
2answers
848 views

Neutralizing TCA washes

Trichloroacetic Acid (TCA) is commonly used for protein precipitation but the wash waste needs to be neutralized prior to disposal. What exactly is required to effectively neutralize TCA waste? Do I ...
5
votes
2answers
351 views

What does the 34/70 in Saccharomyces pastorianus Weihenstephan 34/70 stand for?

I've searched everywhere. No Wikipedia page. No information on NCBI. I searched all occurrences of 34/70 in some primary research articles! The best I've found is this brewery forum where someone ...
25
votes
3answers
9k views

Why do eukaryotic organisms have introns in their DNA?

We touched on introns and exons in my bio class, but unfortunately we didn't really talk about why Eukaryotes have introns. It would seem they would have to have some purpose since prokaryotes do not ...
5
votes
1answer
263 views

How long does it take to stain cells?

I'm never going to run these type of experiments but I do need to have a good idea of their timescale. After I fix my cells, if I stained my cells with histology stains like DAPI, Fluorescein, and ...
5
votes
0answers
115 views

What temperature should mammalian B-Cells be stored at outside of the incubator?

I'm working with murine B-cells. The general protocol is to keep cells on ice to keep them from dying but I've noticed that it makes these cells aggregate and precipitate out. I've heard suggestions ...
8
votes
2answers
6k views

Glomerular Filtration Rate

In practice, when you have vasoconstriction of the glomerular capillaries and subsequently an increase in blood pressure, glomerular filtration rate increases. However, this seems counterintuitive to ...
7
votes
1answer
192 views

When collecting cell lysates for a Western blot, how do I induce di-sulfide bonds?

I would like to conduct a simple dimerization experiment for some protein I'm collecting from a cultured cells. My thought is, that if I'm running a non-reducing, denaturing PAGE gel, then removing ...
7
votes
1answer
3k views

How do Proteins migrate in MES vs. MOPS

My gels look significantly different in MES (2-(N-morpholino)ethanesulfonic acid) and MOPS (3-(N-morpholino)propanesulfonic acid). That is to be expected. What I don't understand is why the simple ...
5
votes
1answer
4k views

How do SDS-PAGE gels differ in a Bis-Tris system vs. a Tris-Glycine system?

Protein migrate differently in Bis-Tris and Tris-Glycine gels. I was curious about the actual reasons why. Do certain gel systems result in a tighter resolution than others?
5
votes
2answers
149 views

Analysing the results of real-time PCR

I want to evaluate the level of gene expression by real-time PCR. I have five controls that are "clinically" the same. I calculated the "fold change" of the target gene regarding each control. What ...
7
votes
1answer
99 views

Soma-soma paired neurons

I'm reading this paper for a presentation I have to do. Since I have no real biology background I encountered a few questions and one I couldn't find an answer using my google-fu. It's about how ...
9
votes
1answer
111 views

Organ cloning - possible to make a non-antigenic organ?

From a J. Neil Schulman article on Organ Cloning: Cannibalizing organs from other people also entails the risk of rejection because of incompatibilities, not only for tissue-typing but also ...
5
votes
1answer
166 views

What evolutionary mechanism caused felines to develop purring?

And why can some felines roar while others meow?
8
votes
1answer
194 views

Why are some bodily fluids more of an infection risk than others?

Whilst on a recent refresher course it was highlighted that when considering risk of exposure to infection from bodily fluids we should be aware of two distinct risk levels: High Risk: Blood Semen ...
6
votes
2answers
604 views

Are cells really the basic unit of all life? [closed]

Please see comments as to the appropriateness of this question on biology SE. All known life on Earth is made up of cells. It is thus safe to say that all known life is characterized by the presence ...
2
votes
1answer
184 views

Why do the sick and unhealthy trees leaf out first in spring?

It's spring. The time of year that trees start to leaf out. I have been watching them, and noticed an interesting pattern. The unhealthy trees of a species leafs out first. I've noticed this ...
11
votes
1answer
3k views

Fish “coming back to life” after being frozen

I've encountered a clip on Youtube showing a goldfish thrown in liquid nitrogen and immediately after to normal water and swimming normally. In the explanation to the clip it says: For everyone ...
9
votes
1answer
1k views

Will the “frog in boiling water not jumping out” work on warm blooded animals

There is the famous saying about a frog that is put in water that are slowly boiling will not jump out until it's too late. I realize it happens because of the frog's cold blood that adjusts to the ...
8
votes
1answer
190 views

Why is maintaining a circadian rhythm important?

What are the real consequences of never maintaining a circadian rhythm? How is circadian rhythm important for health and function? Where did it arise in evolution?
17
votes
1answer
19k views

Why is coffee a laxative?

How does caffeine (or any additional agents) act as a laxative when ingested? I'm interested in the metabolic/signaling pathway.
9
votes
2answers
273 views

Are there differences in DNA between humans of today and humans from 2000 years ago?

Are there any significant differences in our genome compared to the genes of our ancestors from 1000-2000 years ago? And if there are significant differences, do they result in significant ...
9
votes
1answer
128 views

Is there a biophysical causation from local field potential (LFP) to spikes?

Many experiments showed that neurons tend to fire at some phase (usually trough) of local field potential (LFP) oscillations, such as theta or gamma rhythm. LFP is supposedly generated by a population ...
9
votes
3answers
193 views

Does GFAJ-1 use Adenosine triarsenate as its energy currency?

Regarding the bacteria found in Mono Lake, CA that scientists believe uses or can use arsenic in its DNA backbone where life as we know it uses phosphorus (according to their experiments depriving the ...
12
votes
3answers
175 views

Why do some fruits have a much wider range of acceptable sizes than others?

Some fruits such as pumpkins can grow to be 100 lbs. Under different conditions, the same variety of pumpkin can produce a 15 lb. fruit. Both plants are healthy, and look the same except for their ...
12
votes
1answer
211 views

Why do people dying of immune deficiency diseases appear sick?

Please forgive the obviously silly appearance of this question, and/or of the tenor which may come across as flippant or dismissive of real world suffering. My intention is none of the above. As a ...
4
votes
1answer
93 views

Are CN3, CN7, CN9 and CN10 the only Parasymphatetic Cranial Nerves?

It has been my thought for a long time that that is the case but I am unsure about it now, since the parasympathetic tract of colon sigmoideum does not seem to have connection with CN 10. It connects ...
8
votes
2answers
171 views

Electricity generated by the body and its applications?

I recently came across this article from Nature. In it, it states that the snails have "tiny biofuel cells that extract electrical power from the glucose and oxygen in the snail’s blood", and that the ...
1
vote
1answer
87 views

Does the Parasympathetic Tract of Colon Sigmoideum Travel with Nervus Vagus and its Nucleus Dorsalis Nervi Vagi?

I have the following tractus now: nucleus parasymphaticus sacrales -> nervus splanchnic -> ganglion terminalis -> colon sigmoideum The tract is parasympathetic. It suggests me that it should ...
9
votes
1answer
238 views

How are there alternative initiation codons?

According to wikipedia and the original complete sequence of the K-12 genome, there are multiple non-AUG start codons such as GUG and UUG. How is this possible? I'm particularly curious about the ...
6
votes
1answer
240 views

Effect of histidine on the binding affinity of HisP

I was asked the following question by my teacher: A gene regulatory protein called HisP regulates the enzymes for histidine biosynthesis in the bacterium E. Coli. HisP is a protein whoes ...
12
votes
1answer
311 views

Quantum mechanics in biology

There is a growing interest in the applications of non-equilibrium quantum dynamics to describe biological processes (I'm not talking here about Penrose's old theories, but new stuff -- quantum ...
8
votes
3answers
223 views

Spatial resolutions in optical microscopy

I have read that different optical imaging techniques such as such as wide-field microscopy, confocal microscopy or STED microscopy can theoretically achieve a different spatial resolution. ...
6
votes
1answer
195 views

Effect of spaying on the female cat organism and health

Veterinarians often recommend spaying a female cat if the owner does not want her to have kittens. What does biology know about the effect of spaying on female cats' organism and health (apart from ...
7
votes
2answers
478 views

How do we know the brain flips images projected on the retina back around?

Why do we turn images upside down again rather than dealing with them directly, still vertically rotated after passing through our lens? I don't see how that would cause any problems, and how we'd ...
4
votes
3answers
141 views

Robotic surgery for treating cancer?

We can localise cancer cells in the body. We can manufacture materials thin and hard enough to penetrate the body without harming it. So what stops us from creating an automated surgery where the ...
7
votes
2answers
557 views

How does Iota-Carrageenan achieve an antiviral effect?

"Cold Defence" nasal sprays are recommended to be taken either preventatively or in the early stages of a cold. The active ingredient in these sprays is Carrageenan. After some research, the active ...
4
votes
1answer
38 views

How do fibers control muscles?

My professor says Nervus troclearis IV somatomotor fibers supply musculus obliquus superior. and similarly for nervus oculomotorius III Nervus oculomotorius postganglionic fibers supply ...
8
votes
1answer
1k views

Effects of beer on muscle recovery after exercise

I noticed it several times that when I drink beer (even one bottle) after some heavy workout, the next day my muscles are more stiff than other times, and not the same way... Is it because that ...
5
votes
1answer
63 views

Somatosensory System

I have a test in my upcoming Neuroscience class, one of the items on the study guide is: Identify 2 means by which a maintained, constant stimulus produces only a transient excitation of the ...
9
votes
3answers
1k views

Species with reproduction barriers that can both reproduce with a third species

To start with, I do not have a sound knowledge in biology or any formal education in the area. I was told that one of the definition of a species is a reproductive barrier, which means that if two ...
6
votes
1answer
189 views

Brain + ethanol experiment suggestions needed

I need to demonstrate the effects of ethanol on a human brain (or other brain with developed telencephalon) in vitro; ideally the effects on vigilance and/or memory. Could you please suggest such an ...
11
votes
1answer
666 views

Alternatives to TBE buffer for denaturing polyacrylamide gel electrophoresis of DNA and RNA?

I just stumbled upon an article promoting 10 mM sodium borate as an alternative to the well-known TAE and TBE buffers for agarose gel electrophoresis of DNA (Brody & Kern, 2004). They claim that ...
6
votes
2answers
634 views

For how long and how cold should I perform ethanol/isopropanol precipitations of RNA or DNA?

Precipitating nucleic acids using either isopropanol or ethanol is a very common operation, and I've read some very different protocols on the duration and temperature the precipitation should be ...
6
votes
1answer
547 views

Do immature fruits perform photosynthesis?

Most immature fruits are green: peppers, pine cones, plums, lots of them. I want to know if the green is from chlorophyll in the cells. Do the fruit cells perform photosynthesis? When you cover a ...
10
votes
2answers
3k views

What is the advantage of using starter cultures for growing bacteria?

Many DNA isolation and protein expression protocols contain instructions to use a starter culture of E. coli that is then used to inoculate the main culture. What are the advantages of using starter ...
10
votes
3answers
791 views

Why do people say that trans fatty acids are bad for your health?

I've heard from several sources that trans FAs are bad for you and their consumption will lead to cardiac problems, and that they are indigestible. But I also learned from biochemistry that they are ...
6
votes
1answer
1k views

Why does the T7 RNA Polymerase require a reducing environment ie. DTT

Every bloody protocol suggests adding in DTT when doing in vitro RNA transcription. Why? The rationale seems to be that the cytoplasm traditionally has a reducing environment but as the only protein ...
12
votes
3answers
463 views

Why is there a difference in the rotation of the tail fin in fish compared to marine mammals?

I've been thinking about this one, but I can't seem to find what causes this difference. All fishes that I've seen have their tail fin positioned vertical: But all the marine mammals I know have ...

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