3
votes
1answer
120 views

What is range of the number of individual organelles in cells

What is the range of the number of individual organelles in a cell? I am not a biologist but I understand that there's one nucleus and sometimes lots of mitochondria, so I am after the total number. ...
4
votes
2answers
2k views

How can I resuspend a cell pellet without harming the bacteria?

When using a preculture with Ampicillin in my protein expression, I have to get rid of the preculture medium to avoid carrying over too much beta-lactamases that will destroy the ampicillin in the ...
1
vote
1answer
135 views

How do axon terminals report to the soma?

It is important to bear in mind that the distance between a neuron's axon terminal and its soma can be extensive, up to about 1m in the human body. The fastest transport along the axon is 400mm/day ...
5
votes
1answer
377 views

How to Design an siRNA Experiment?

I'm going to undertake an siRNA experiment soon, but I have only read about them. I want to address the role an enzyme plays in processing a protein. From what I understand, I will need to pick two ...
5
votes
1answer
2k views

How does formaldehyde cause protein-DNA crosslinking?

How does formaldehyde cause protein-DNA crosslinking? I would guess it's because the strongly polar water molecule interacts strongly with polar residues on a protein-DNA complex, and adding a less ...
0
votes
0answers
53 views

Western blotting of lung samples [duplicate]

I have been working on lung samples to perform western blotting. I have two related questions about this: I get very nonspecific results: at times nothing at all, at times it glows on membrane but ...
3
votes
1answer
100 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.
8
votes
2answers
200 views

Solution based measurement of Solvent-Accessible Surface Area of macromolecules

The Solvent-Accessible Surface Area (SASA) is a valuable metric for looking at protein folding and protein-protein interactions. However, this measurement is typically done by calculating the SASA ...
5
votes
1answer
213 views

Are there eukaryotes without introns?

This question on the function of introns in eukaryotic genes made me think: I know that more basal organisms have smaller introns and fewer alternatively spliced exons compared to mammals. But are ...
7
votes
2answers
209 views

During famine, does the human body do anything to prioritize which organs receive nutrients?

When food is scarce, the body slows its metabolism. Are there any other systems or processes that encourage prioritization of organs?
1
vote
1answer
175 views

Parthenogenesis in Bees

Parthenogenesis is defined as: "A type of asexual reproduction in which egg develops without fertilization to form a new individual." If parthenogenesis takes place in bees, a drone or male bee is ...
2
votes
2answers
610 views

How prevalent is Taq polymerase in adding 3' A overhangs to the PCR product?

I am conducting a mutagenesis on a gene in vivo of which I need to ligate into an expression vector. The primers I have designed overlap restriction sites of which I plan to use to ligate into the ...
1
vote
1answer
295 views

Why does the hydrolysis of ATP increasing entropy increase the Phosphoryl-­‐transfer Potential?

I am currently taking a biology class. I do not understand this concept. I understand that the electrostatic repulsion of the negative charges, resonance stabilization and hydration stabilization all ...
0
votes
1answer
271 views

Definition of Dye- Reduction Test?

Can some one give a simple explanation or definition on what a dye-reduction test is.
1
vote
1answer
140 views

Why does contracting the iris allow less intense light to go in?

The iris contracts automatically in the presence of bright light. This makes a flashlight appear bright in darkness, but outside in daylight you can't even see it's light. The iris is changing your ...
2
votes
1answer
119 views

EGFR, sialylation, and cancer progression

EGFR (epidermal growth factor receptor) has been intensively studied in cancer and treatments have been developed to inhibit EGFR signaling. Sialylation of EGFR is known to block dimerization and ...
1
vote
0answers
46 views

Experience with Detox Cloning

I just saw this paper. A Highly Efficient Molecular Cloning Platform that Utilises a Small Bacterial Toxin Gene I was curious if anyone had experience with this cloning strategy using the IbsC ...
9
votes
1answer
621 views

What is the gas inside a Capsicum pepper, and how does it get there?

Every time I make fajitas, I cut into bell and chili peppers and notice how hollow they are. I always think to myself: what is the gas inside this pepper, and how does it get there? Perhaps Capsicum ...
4
votes
3answers
168 views

Is it technically possible to make someone see something when their eyes are closed?

I'm writing a little article and need any information about how human vision works and latest technologies and discoveries around. Actually its not a professional article. Its for a group of my ...
0
votes
1answer
32 views

How Common are Paraneoplastic Syndromes in Cancer Patients?

I recall reading around one in four cancer patients will suffer a paraneoplastic syndrome during the course of their illness but I can't find where I read this and I can't find any reliable sources to ...
6
votes
1answer
142 views

Alternatives to fittest-win and Moran processes as simple mathematical models of selection

When modeling selective sweeps as a micro-building block in models of macroevolution (not to be confused with misuses of this in creationist arguments), I use the fittest-win model of selection as a ...
6
votes
1answer
146 views

If life is discovered on another planet, will it likely be classified using the current domain/kingdom/phylum system?

This may be a stupid question showing my lack of understanding of taxonomy, but I was wondering if the current classification system we use contains broad enough categories to include new life forms, ...
5
votes
1answer
111 views

Significance of basal lamina for outer layers of epithelium

In stratified (not pseudostratified) epithelia such as the epidermis, what purpose does the basal lamina serve for the outer layer cells which do not even stand in contact with it? Also, how do these ...
5
votes
2answers
427 views

What metabolic activities are performed by a developing human fetus's liver?

I understand that organ function varies with the stages of development. Does a fetal liver EVER perform lipogenesis, gluconeogenesis, make bile, etc? Or does it only begin performing these actions ...
3
votes
1answer
141 views

How might gene clusters like the lac operon evolve?

The obvious answer for a gene cluster is gene duplication and mutation of one or both genes. But the genes in the lac operon seem not be so functionally/structurally similar (as compared to the Hox ...
6
votes
2answers
687 views

How long can I store autoclaved disposables and reagents?

I want to stock up on autoclaved disposables, such as Eppendorf tubes, pasteur pipettes etc., and some buffers. If I don't open the container after autoclaving, how long can I store autoclaved ...
1
vote
1answer
236 views

What is the brightest color a light source that only emits blue frequency light can achieve?

Let's say there is a luminous light bulb that only emits blue light, and you (or a camera if you prefer) look at it from a close distance. Will the maximum brightness perceived not have any "white" to ...
0
votes
1answer
266 views

Least painful way to die

There is a lot of talk about inhumane treatment of animals and how we don't kill them in the proper way. I wonder how much research is done on this subject. What is the overall least painful way for ...
0
votes
1answer
591 views

DNA gel extraction: chemical contaminants

I am performing a gel extraction to purify DNA after a double digest with EcoRI and BamHI. After the gel extraction I need to complete a ligation step before bacterial transformation. The problem I ...
2
votes
0answers
46 views

Onset of Autophagy

Fasting and Intermittent Fasting (IF) have been proven to start autophagy (cellular self-digestion). How long does the average man and woman have to wait for autophagy to begin? Does diet prior to ...
1
vote
1answer
40 views

What does “Psychomodulatory” mean in the context of potentially psychoactive drugs?

What does "Psychomodulatory" mean in the context of potentially psychoactive drugs? That is, in this journal article http://www.sciencedirect.com/science/article/pii/S0028390812001931 in the ...
0
votes
1answer
465 views

What's the difference between life expectancy of cigarette smoker and general population?

Some say that smoking cigarettes will shorten lifespan. By how many years is the lifespan of a typical smoker shortened? What are the common cause(s) of death among smokers? Are there any known ...
1
vote
1answer
50 views

How are geneticists able to isolate gene functions?

As an example, this Scientific American article describes a known area in the dog genome that metabolizes carbohydrates. How is it that researchers are able to determine specific functions such as ...
3
votes
1answer
2k views

What factors are known to affect evolution?

My understanding is that the possible mechanisms of evolution are: Environmental changes Cultural/mating preferences Population Immigration Genetic Mutation Am I missing anything? I've heard that ...
1
vote
0answers
76 views

Can mammals from different species reproduce?

I'm curious on how genetically different can two animals be in order to reproduce. Could they belong to different species? One example is the mule which is the offspring of a donkey and a horse, in ...
8
votes
1answer
864 views

Under what circumstances and why is terrific broth preferred to LB broth for E.coli growth?

Terrific Broth will result in a greater density of cells compared to LB but I have certainly seen it isn't as effective for the protein production of certain proteins compared to LB or defined media. ...
4
votes
1answer
1k views

What is immunopanning (vs. immunoprecipitation and FACS)?

I had never heard the term before today. From what I can tell, it's using antibodies to purify a cell population of interest. I would appreciate more details, especially in how it differs from ...
0
votes
2answers
130 views

Why do some people find vegetables so repellent when evolutionarily they should find them an attractive and thus tasty food?

Why do certain people (especially kids) find vegetables so "repellent" when evolutionarily they should find them an attractive and thus tasty food? I ask this question because if Darwin's theory of ...
2
votes
0answers
67 views

Is there a Pharmacology Textbook that Satisfies the Conditions listed in the Body of this Question?

The conditions are: As extensive and explanatory as Goodman and Gilman's The Pharmacological Basis of Therapeutics, Twelfth Edition With additional extensive and thoroughly explanatory information ...
2
votes
1answer
110 views

Expanding the SETI initiative to seek intelligent data within DNA sequences?

I've recently read a couple articles dealing with long term data storage, and DNA was suggested as one of the prime candidates for long term storage of digital data additionally, there is this article ...
1
vote
1answer
104 views

What is background binding?

I'm reading a journal article about mitochondrial protein import and it mentions that one of the mutant proteins tested showed background binding with another protein. What the heck is background ...
3
votes
1answer
310 views

Can Naegleria fowleri enter through the eyes ( example rinsing/splashing eyes with water)

I understand that it primarily enters the body through the nose by by "feeding on the olfactory neurons in the nose" as answered here in a different question. Would the nerve cells in the eyes present ...
3
votes
0answers
25 views

A program for cell motility assessment with a batch process function?

Cell motility assessment is a branch of experimental biology or medical science. One example could be an assessment of treatment effects on sperm motility of an animal. The standard procedure involves ...
1
vote
1answer
66 views

Is stereo olfactory ability restricted to humans?

Most animals I see around seem to have two nostrils - humans, snakes, birds, fish .. and so on. From reading online I see that 2 nostrils provide a stereo olfactory effect. This stereo effect is ...
10
votes
2answers
170 views

What makes E. coli yellowish?

LB, TB media, and yeast extract are also yellow but at the heart of the question. What chemical(s) make E. coli yellow?
4
votes
1answer
128 views

What limits the size of fish compared to marine mammals?

The largest extant fish species is the whale shark (Rhincodon typus). With a length of 13 meters and a mass of about 20-30 metric tons, the whale shark is relatively small compared to the largest ...
0
votes
0answers
50 views

what's an ethics-friendly way to measure the protocol of electric shocking mice?

We have to measure the protocol of electric shocking mice. The mice are head-fixed, we have to guarantee that the electric current is significant to make the mice learn, but not too big to make the ...
2
votes
3answers
1k views

Improving Gel Extraction yields

How can I improve my Gel Extraction yields. We use the standard protocol from Qiagen, gel extraction, dissolve in QG buffer at 42C and purify via anion exchange columns. However, with 500 ng we ...
4
votes
1answer
188 views

What is a simple protocol for staining cells in suspension?

I am an engineering student studying how electric fields affect cells, specifically the phenomena of electroporation in living cells. I know that electroporation is widely used for introducing genes ...
2
votes
1answer
178 views

One flybase gene number (FBgn), many Affymetrix Id's

I am trying to convert a set of Affymetrix ID's, like this one 143053_at_3745, to Flybase Gene Numbers (FBgn) like this one FBgn0000015. I have downloaded the Flybase file required to do so (as ...

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