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25 votes
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Why are drug dosages so high in some mice studies?

Mice are simply different from humans; they have different metabolism, different lifespan, different body size. Generally, for a first order approximation, one might scale simply by body weight to ...
Bryan Krause's user avatar
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6 votes

Can LSD in very small amounts increase mental ability?

The phenomenon you are referring to is called microdosing. It was brand-new in terms of research focus when you initially asked your question, and it is still a fairly novel and little-studied subject....
TheChymera's user avatar
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6 votes

Why did scientists think humans had 100,000 genes (before the Human Genome Project)?

Human genome is 3.2Gbp (giga=billions of basepairs). If you assume there are 100k genes, this yields around 32kbp (kilo=thousands base pairs) per gene. Before human genome project, let's say before ...
aaaaa says reinstate Monica's user avatar
6 votes
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What would "N" and "V" stand for in DNA barcoding?

It is standard IUPAC nomenclature to write bases that are not uniquely defined. For example, "N" means "any base", but "V" means "A, C or G, but not T". See the full list here
Mowgli's user avatar
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6 votes
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What insect/invertebrate species evolves fastest?

Drosophila melanogaster. (fruit-fly, pomice-fly) Image, public domain, via Wikipedia 2022. Development time is under ideal conditions 8.5 days (at 25 Celsius, 77 Fahrenheit), the females produce ...
Jiminy Cricket.'s user avatar
6 votes
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Is it viable to make liquid potassium ferilizer through dissolving very small amounts of potassium chloride in water

the issue here is the chloride not the potassium. Potassium chloride is very soluble in water. but you could be killing your crops/garden when you spray it on. Most plants do not tolerate much ...
shigeta's user avatar
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5 votes
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Why did scientists think humans had 100,000 genes (before the Human Genome Project)?

There's actually no need to speculate on the answer to this question since scientists have published their estimates and methodology, as is their way. The following paper is a good review: Fields C, ...
canadianer's user avatar
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5 votes
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Ensuring all individuals are genetically identical before experiments

For fruit flies one usually wants pure lineages for specific alleles, corresponding to distinct phenotypes. One cannot arrive to such a state by merely enclosing the flies for many generations - in ...
Roger V.'s user avatar
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5 votes

how to extract garlic fructan?

It seems that the basic method is just a water extraction - soak some powder from your garlic in water for a period of time. Ideally you would determine experimentally the optimal time and temperature ...
bob1's user avatar
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4 votes
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How can enzymes be immobilised on glass?

Glass can be functionalized by organosilanization so that biomolecules can be covalently attached via some cross-linker. As an example, one might aminosilanize the glass and then cross-link their ...
canadianer's user avatar
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4 votes
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Why is EcoRI supplied with a unique buffer when it is allegedly 100% active in universal buffers?

Activity toward the desired substrate sequence is not the only concern in evaluating a restriction enzyme buffer system. In addition, you need to be concerned about so-called "star activity", or ...
R.M.'s user avatar
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4 votes

Why did scientists think humans had 100,000 genes (before the Human Genome Project)?

I don't know much about the evolution of thoughts on the subject but I would suppose that the estimate of 100,000 genes is probably caused by the one gene - one enzyme/protein ideas The one gene–...
Remi.b's user avatar
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4 votes
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How can I measure the population growth of yeast?

The standard way to measure growth in a liquid culture is to measure the optical density (OD) of the solution – basically, how cloudy it is. Bacteria or yeast in a solution will absorb light that ...
divibisan's user avatar
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4 votes

Question in gel chromatography experiment

Within reason, you can basically use any buffer you like with Sephacryl S-100, provided that is suits your purpose in terms of protein/enzyme stability, and phosphate-buffered saline sounds ideal. ...
user338907's user avatar
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3 votes
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What are "primary amino acids and secondary amino acids"? Context: analysis of amino acid content using reversed-phase HPLC

I would guess that 'secondary' refers to amino acids that have been derivatized in some way, possibly by reacting with o-phthalaldehyde. (To measure the fluorescence of an OPA-derivatized amino acid, ...
user338907's user avatar
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3 votes

Quantifying DNA in a band on gel electrophoresis

All three methods could be used to measure the amount of DNA. However in practice, method 2 (estimation by dye brightness) typically works best in a normal workflow. It really depends on what you plan ...
tswei's user avatar
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3 votes

What bacteria results in a Gram +ve cocci and catalase +ve? What test comes next?

At this point you have staph, you can use this flow chart (from here) to figure out what staph exactly. If the test comes back as coagulase positive be very careful as Staph aureus is pathogenic.
thewormsterror's user avatar
3 votes

How can I estimate the total number of yeast cell in a medium?

Determination of cell concentration using a microscope is usually done by using a hemocytometer, also called counting chamber or Neubauer-counting chamber. Basically, you count the cells in a defined ...
cako's user avatar
  • 141
3 votes

What is a (preferably) flying carnivorous insect that hunts adult fruit flies at a rate that doesn't threaten extinction?

Biotic fruit fly pathogens / predators. You don't need every single one for a basic project. Here are 2 types. Parasitoid wasps Parasitoid wasps lay eggs in larva. Drosophila in the wild suffers ...
Willk's user avatar
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3 votes
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What is a "marker-matched" plasmid?

It is where a control plasmid is used - this is usually an empty vector or a non-target vector with the same "marker" on the plasmid. The marker is often one that is either used for ...
bob1's user avatar
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2 votes

How would one determine whether a chemical will upregulate a certain class of proteins?

One way of examining this is by looking at the transcriptome as a whole before and after the introduction of the chemical. I would use microarray or next generation sequencing RNA-seq technology to ...
Dror Hilman's user avatar
2 votes
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What does the phrase 'background level' mean?

The phrase “background level” is generally used in an experimental context where you are measuring the effect on a variable of some agent or stimulus. You might expect that your control condition(s) — ...
David's user avatar
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2 votes
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What is the best way to analyze non-quantitative mass spec hits from an immunoprecipitation pull down?

If they are available, talk to the people who analysed your data. Using their knowledge is intelligent. I will assume two critical steps are completed. First that your results have been searched ...
Michael_A's user avatar
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2 votes

Does cell phone radiation promote longevity?

"I'm curious to know why more people haven't commented on this result in news outlets" Because for once the news outlets appear to be behaving responsibly, and waiting until the results are ...
David's user avatar
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2 votes

Does cell phone radiation promote longevity?

If you read the discussion, and also the full contents of the PDF which include some reviewer comments, there is concern about the control group: The survival of the control group of male rats in ...
Bryan Krause's user avatar
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2 votes
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Why use embryonic neurons to study protein knockouts/mutants in long term potentiation?

Some suggestions, there may be more: 1) The knockout may not be viable to adulthood (the animals die). Perhaps heterozygotes are viable, but to test the full knockout you need a homozygote. 2) Even ...
Bryan Krause's user avatar
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2 votes
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How is the flicker fusion rate interpreted as an on-off rate?

Short answer A light flashing at 50 Hz means there are 50 flashes of light per second. The unit hertz means cycles per second. 1 cycle is the time it takes for the light to be ON and OFF. 50 Hz cycle ...
AliceD's user avatar
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2 votes
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How is the gradient in density gradient centrifugation made?

Sucrose gradient separations are an example of a rate-zonal centrifugation technique (fair technical document on centirfugation separations). The idea is you layer lighter sucrose solutions on top of ...
CKM's user avatar
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2 votes
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Are there situations where in vivo results work better than in vitro results would have shown?

Differences between in vitro and in vivo results are (unfortunately) very common! Somehow, all failed clinical trials (and many preclinical trials) are large-scale examples of the discrepancy between ...
Mowgli's user avatar
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