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One of the cornerstones of research ethics worldwide is the Nuremberg code, which was formulated shortly after the Second World War and set off by the cruelties performed by the Nazi Doctors. The Declaration of Helsinki, which is currently widely used as the guiding principle of research ethics, was directly inspired by the Nuremberg code. Interestingly, ...


11

kmm's answer is correct; I just want to add some of my points on what kind of data should follow Gaussian distribution. Unless you know from observation that a process doesn't follow a Gaussian distribution (e.g., Poisson, binomial, etc.), then it probably does at least well enough for statistical purposes. I won't fault kmm for this statement ...


9

Wow that can vary from a couple of months and a few thousand dollars to a lifetime and millions of dollars. I can give a couple of examples, but this is an extremely broad question. Wet science is not cheap might be the message here. Gene Ontology terms are meant to cover all biological roles known for genes. Terms are added and retire regularly. They ...


9

You raise two issues, both of which might be better suited for stats.SE, but I think the questions are suitably biological to warrant an answer here. Do most biological processes follow a Gaussian distribution? Unless you know from observation that a process doesn't follow a Gaussian distribution (e.g., Poisson, binomial, etc.), then it probably does at ...


7

The technique described here is called microarray. Your question has given me an opportunity to put forth one of my opinions about certain problems of gene expression studies. Gene expression is a measure of the activity of any gene. If the gene performs its activity in the form of a protein, then its expression should be a measure of the protein. If a gene ...


7

You could do different things: First you could, as you say yourself, sequence the complete genomes of the strains from a biofilm and compare these with some, which do not form biofilms. This may give you an idea which genes are involved when they are present in the "biofilm genome" but not in the other. The proof would be to disrupt these genes either by ...


6

Pseudomonas bacteria are generally not difficult to grow: Rugged and opportunistic, Pseudomonas use a wide range of nutritional sources, even very simple nutritional environments without any organic compounds. - Sigma For specific species, you'll want to use a selection medium. Sigma-Aldrich has a number of commercial products for selection and I'm sure ...


6

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 1990, people were isolating a lot of genes from human-derived tissues. You can use google scholar to find relevant papers. From quick search, you can see that ...


6

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


5

There is evidence that copper pots have antibacterial effects when used for storing drinking water (Sudha, et al. 2012), so the copper coins will probably have a similar effect. The easiest way to test this at home would probably be to buy a test kit from an online vendor - these are relatively inexpensive. Some Googling produced this website [appslabs.com....


5

I am assuming you want to monitor these traits in controlled conditions because in wild type conditions it will be real challenge to monitor in details unless you have easily accessible way (like leave surface area and related visual traits). Remember these techniques will change according to your plant/seed and your study interest. Lot of things change ...


5

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, Adams MD, White O, Venter JC. 1994. How many genes in the human genome? Nature Genetics 7:345-346. Below are some truncated excerpts from the paper but, if ...


4

As with so many things, it depends. Also, I'm a bit unclear when you say antibody-receptor interaction, do you mean that you have an antibody that's specific for a receptor, or that you're studying Fc receptors binding to antibodies? (for the following, I assume the former) For most cell types and most cell surface molecules, simple antibody binding isn't ...


4

There are several reasons why a lab might choose to get DNA from lymphocytes instead of whole blood. Generating genomic DNA from whole blood is not necessarily the best idea, as all the excess protein (mainly hemoglobin from RBCs) needs to be gotten rid of at some point. By narrowing down your input to just include cells that have DNA, you lessen the amount ...


4

Addition to Chris' answer. If you do not have a strain that doesn't produce biofilm then you would have to screen for the genes that are involved in biofilm production (this goes for any phenotype). In earlier times people used to do this by random mutagenesis with mutagens such as EMS (Ethyl Methanesulphonate) or UV. Nowadays it is possible to build a ...


4

The short answer is that it is likely a bad experiment; being that it would be expensive and is not likely to provide useful new information. The long answer (i.e. why) is identifying an interesting target gene (e.g. caspase-9 in breast cancer) is only the first step, and considerable study of what is already known is required before planning an experiment (...


4

As an elaboration of my comment. Summary: Replication is required in GWAS studies to account for non-random technical biases. An example of such bias is, for example, a chip used for genotyping giving consistently incorrect genotypes for a locus. In this situation adding more subjects will not correct for this effect and therefore the only solution is to ...


4

You are right to be suspicious. I would contend that, in most situations, hypothesis tests based on the normal distribution are not appropriate. If hypothesis testing is needed, a permutation test should almost always be used. As WYSIWYG points out, there is no reason to assume a measurement is normal distributed without strong a priori knowledge. The ...


4

All options given have advantages but become disadvantageous depending on experiment you are trying to do. Here question is asked for "breeding experiment". In these experiments it is very important to keep track of genetics. If females mates with males of some undesired genotype, it will ruin your experiment objective. As option (c) is 'mating soon after ...


4

Although it's not stricly about biology, A short history of nearly everything by Bill Bryson, especially chapter 5, is a good start to look for historical experiments.


4

The Eighth Day of Creation by Horace Freeland Judson is quite good, in the genre you're looking for. Also, Science as a way of Knowing may fit the bill.


4

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 enzyme of interest with glutaraldehyde. For what it’s worth, urease activity can be measured in solution.


4

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–one enzyme hypothesis is the idea that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects ...


4

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 passes through it, making it more cloudy (or turbid). Within a certain range of turbidity, the OD of the solution is directly proportional to the concentration of ...


4

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. There are sometimes a small amount of positively or negatively charged groups associated with a gel-filtration resin, introduced during the manufacturing process, ...


3

Depending on the exact goal of the experiment, the researchers may back-cross both to smooth out genetic variation between individuals and to potentially normalize expression of a transgene, although once you get past the chimeric stage gene expression should be fairly stable. In my experience, back-crossing allows you to generate a genetically-altered mouse ...


3

I think you might be better advised to try plating out samples of the water and counting bacterial colonies. There has been some good advice on doing basic microbiology at home elsewhere on this site.


3

My personal favourite is OpenWetWare. Think wikipedia for scientific protocols and an open access lab notebook. There's a problem with this things. Despite the common stereotype of scientist being open and good at sharing, my experience is the opposite. Many laboratories are not good at all in sharing their techniques/secrets. They will share the basic ...


3

There is also protocol online, but without tags, only sorted by category. It could nevertheless be interesting.


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