25 votes
Accepted

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 ...
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9 votes
Accepted

What are the potential dangers (if any) facing the twin girls recently born in China with their CCR5 gene modified?

Important notes: I am not going into the ethical aspects of editing/removing CCR5 in human embryos, neither will I discuss potential effects of introducing that mutation into the human population....
  • 4,316
5 votes

Can one conduct “novel” research without an advanced laboratory? Has it been done by school pupils?

I can point to two published papers in which students performed useful experiments. The present study (on the vision of bumble-bees) goes even further, since it was not only performed outside my ...
  • 14.1k
5 votes
Accepted

Short, concise, practical manual for doing experimental biology

Molecular Cloning is updated and in its 4th edition. Every lab used to have it. Its comprehensive, but really no book could be complete.
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4 votes

Was the Okazaki fragment experiment ever replicated?

Formation of Okazaki fragments in polyoma DNA synthesis caused by misincorporation of uracil - Brynoff, et.al. Cell; Volume 13, Issue 3, p573–580, March 1978 one of many, but you only need one to ...
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4 votes

Short, concise, practical manual for doing experimental biology

Along with @shigeta's answer, I'd highly recommend Springer/Humana Press's series Methods in Molecular Biology, which started out as just a single collection of protocols (as I recall...) and is now a ...
  • 14.9k
4 votes

Did Mendel believe that proteins are hereditary substances?

The first person to directly indicate a linkage between the hereditary material and enzymes was Garrod in 1902, based on the observation of the hereditary enzymatic disorder alkaptonuria. This is ...
3 votes

What are the potential dangers (if any) facing the twin girls recently born in China with their CCR5 gene modified?

2019-09-29 update: the answer below is based on a scientific paper that seems to have a major flaw, see https://www.statnews.com/2019/09/27/major-error-undermines-study-suggesting-change-introduced-in-...
3 votes

Has there ever been a published experiment to take a viral "census" of a human subject's blood?

You wouldn’t try to isolate viruses, this being the 21st century. You’d perform metagenomics analysis, which is much more sensitive. That’s been done several times. Two examples: Anellovirus ...
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3 votes
Accepted

Suggestions for self-studying experimental techniques

I cannot more highly recommend Molecular Cloning 4 ed.. It is a really comprehensive text which covers numerous molecular biology experimental techniques including different types of PCR. EDIT: Also,...
3 votes
Accepted

Which wavelength to use to determine algae using a colorimeter?

From Biotek I learned the following: Spectral scans of algae cultures demonstrate significant absorbance below 400 nm as well as two distinct absorbance peaks at 440 nm and 675 nm (Figure 1). Cell ...
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3 votes
Accepted

Transmembrane Protein Problem

I made a quick sketch on the basis of the information you gave (this is not to scale): Aminoacid 5 (aa5) of the protein is on the outside, aa90 is inside the membrane. What we don't know here where ...
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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 ...
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3 votes

Does beta-actin have to be consistent in Western Blots?

The long and the short of it is that your actin bands do not need to be consistent so long as you can normalize and have met the quite stringent conditions for normalization to be effective. For ...
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2 votes

Transmembrane Protein Problem

Membrane proteins are usually drawn as topological digrams with two parallel horizontal lines representing the membrane. lines as 'extracellular' and below the lines as 'intracellular' for instance, ...
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2 votes
Accepted

What microscope/magnification would I need to observe P. Acnes bacteria?

I agree with canadianer that chemical tests are generally more useful for identification. However, morphology does help and some staining techniques can be useful for identification (the Gram stain ...
2 votes
Accepted

Can we directly stimulate M cones in retina with current technology?

You've probably seen the news reports by now, in which researchers targeted and stimulated individual cone cells in the eyes of volunteers: "The elementary representation of spatial and color vision ...
2 votes

What data would Meselson and Stahl have expected if DNA replication was dispersive rather than semiconservative?

A few baseline ideas should be understood. 1. The assumption is made that Meselson and Stahl's cell line at the start of the experiment contains DNA composed entirely of the $N_{15}$ isotope. 2. DNA ...
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2 votes

Monitoring fish growth

Per your prompt, there are three new brands of fish food, but... You have been using a standard type of food that has worked reasonably well. I suggest you include the "standard" fish food as a ...
  • 7,779
2 votes

Monitoring fish growth

This is a good experiment! 3 types of food: ok 9 tanks: ok Apply different treatment randomly - no! You are right - no way to tell with random. It is like comparing McDonalds to vegan diet - you ...
  • 2,926
2 votes

What advantages could there be for using the unseen variant chosen by He Jiankui instead of the naturally occurring CCR5-∆ 32 mutation?

Possibly He Jiankui was using Cas9 without a template DNA. If so, this generates double-stranded breaks that are repaired through processes such as non-homologous end joining (NHEJ) that often ...
  • 5,502
2 votes

Why didn't these scientists restore electrical activity in this pig's brain?

Restarting electrical activity would mean that at least parts of the brain become active again and possibly restoration of almost all cognitive functions. While this would be a tremendous scientific ...
  • 4,316
2 votes
Accepted

What determines the physical appearance of a tangible amount of bacteria or viruses?

There is no one answer to this question, any more than there is a single answer to the question of what color, texture, or size a mammal is. To get a sense of some of the diversity out there, the ...
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2 votes
Accepted

Why is neutralizing important when carrying out the Benedict test?

Benedict's reagent is used mainly to test the presence of reducing sugars. However, it can also be used to test non-reducing sugars indirectly. For that to happen, non-reducing sugars are first ...
2 votes
Accepted

Has anyone tried the petri dish experiment with and without mask but at the side?

While I'm not sure about the petri dish experiment, I will answer the main question I think you're asking: how important is the air that escapes out of the sides/top of the mask? This question is ...
  • 3,263
2 votes
Accepted

Methods to obtain the mass distribution of an ensemble of bacteria?

Short Answer: Flow Cytometry or Dynamic Light Scattering (DLS) might be the most "mainstream" methods out there that might give you a size or volume distribution. Then you need to do some ...
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2 votes

Methods to obtain the mass distribution of an ensemble of bacteria?

In addition to Markur’s answer, Coulter counters suck the cells through a small capillary (in an electrolyte solution), which also serves as a conductor in an electrical circuit. They then estimate ...
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1 vote

Fluorescent protein tags and colocalisation

"Are protein A and B co-located?" The answer is that it depends. Since your test question included the word "necessarily", this means that the answer to the test question is no. All you have to do is ...
  • 3,751
1 vote

Biology Intuition and Origin of the "facts"

Googling "landmark experiments in biology" came up with a lot of hits, what was wrong with the experiments cited in any of those works? Mendel's pea experiments should be easy enough to understand. ...
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1 vote

How are fMRI responses to auditory stimuli measured?

I could have found this article earlier, but as things go, I didn't. But possibly it contains most of what can be said to this question: Jonathan E. Peellej, Methodological challenges and solutions ...

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