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14

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, ...


6

A "normal" centrifuge = piece of laboratory equipment, driven by a motor, which spins liquid samples at high speed to allow centripetal acceleration to separate substances of greater and lesser density. Without further information regarding the method you read, a "vacuum" centrifuge might be a reference to one of the following: Ultracentrifuge a ...


5

Prepared or conditioned for storage would probably be perfectly acceptable. If you're looking for a single-word equivalent, in this case, I would translate as stabilized. From dictionary.com: stabilize [stey-buh-lahyz] verb (used with object), stabilized, stabilizing. to make or hold stable, firm, or steadfast. This seems ...


5

A simple method would me to express a fluorescent protein in the cell that specifically localizes to mitochondria. mito-dsRed is a Red Fluorescent Protein which has that property; it can be expressed from a plasmid. Using fluorescent microscopy and image analysis, you would be able to measure the geometric properties of the mitochondria. This can be done at ...


5

In most cases when you perform NMR experiments on proteins you detect the signal on the protons. Even if you're looking at other nuclei, in the end you transfer the magnetization to a proton and detect that signal. This is simply the most sensitive method due to the high gyromagnetic ratio of 1H, and this is the method that is labeled "inverse" in your ...


5

Dear respected person, I am not a professional botanist, but I adore gardening, and would like to help you as much as I can from my humble garden experience. As far as I have experienced, not all plants have stems which root when put in the ground. For instance, I have a plant called Bouganville Tom Thumb (I apologise for any spelling error). I once ...


5

Neural info is contained in spike trains, mainly in terms of spike frequency and related parameters. These spike trains in individual neurons can be measured by techniques like patch clamp and Ca2+ imaging. These techniques are all pretty sophisticated and computer assisted for sure. However, by recording of action potentials in e.g. the optic nerve, we ...


4

The answer to this question depends on how you want to preserve it - as a pinned specimen (also dry preservation, most common) or in a liquid. If you want to pin it, placing it in a jar with a cottonball soaked with ethyl acetate (also used in killing jars) is good because it softens the muscles and makes the insect easier to pin and mount. Beetles are then ...


4

If you're not already doing so, make sure you set up Kohler illumination every time you use the microscope -- see this tutorial by Steven Ruzin. The lamp or the phase ring may be misaligned. There are usually small hexagonal set screws on the lamp housing and the condenser, respectively, to adjust these. Imaging near the edge of a dish or well can lead to ...


4

There are existing instruments commercially available to measure hemoglobin-oxygen saturation curves. Whole blood or lysed blood can be used; I would expect the instrumentation to come with specific directions for sample preparation because it may depend on the exact equipment. These devices use a spectrophotometer to measure saturation, taking advantage of ...


4

Colorado State University has two helpful pages that explain the main procedures (h/t Tom). Semen Collection goes through the 3 ways that are used to collect semen from animals. Semen Collection from Bulls helpfully expands on bulls specifically: Semen is most commonly collected from bulls in bull studs using an artificial vagina, as described below. ...


3

Send soil samples to a soil lab (e.g., here). They will likely use the Mehlich III extractant method to extract and quantify the nutrients (most importantly the bases such as Ca, Mg, K, and Na). Will cost less than $25.


3

Leeches: According to Taube (1966)$^1$: The adults of American leeches range from about 1/4 inch to 12 inches in contracted length. Because leeches can bloat to more than 10x their "normal" size after a meal (and can undergo up to a 300% change in length), it seems that measuring a leech at anything but their contracted state would lead to wildly ...


3

Generally yes: streptococci are catalase negative while staphylococci are catalase positive. The catalase test is important in distinguishing streptococci (catalase-negative) [from] staphylococci which are catalase positive. Unlike Staphylococcus, all streptococci lack the enzyme catalase. However, there are exceptions to every rule: Catalase ...


3

This procedure is referring to chemical extraction, which is a separation process used in chemistry (and biochemistry) to isolate compounds of interest by using two immiscible phases in which the compound of interest has differential solubility. For example, in a liquid-liquid extraction, often one of the phases contains a polar solvent like water, and the ...


3

From what I understand, the answer is; it depends. As you point out in the comment to Remi.b, contrasts are standardized by branch lengths (which are assumed to be proportional to "evolutionary time") before they are analysed (to obtain standardized independent contrasts). However, branch lengths can be come from a number of different sources (divergence ...


3

Western blot, though is a commonly used technique and is relatively simple to do, has some issues: Low throughput: it is difficult to analyse multiple proteins simultaneously Limited cross comparability: since antibodies to different proteins can have different affinities, they cannot be compared with each other. Low sensitivity Not very quantitative LCMS ...


3

EEGs are often analyzed in the frequency domain, where signals are subjected to spectral analysis, typically by Fast Fourier Transformation, or FFT. What an FFT basically does is decomposing a signal in the time domain into one in the frequency domain. It does this by decomposing the input signal (any signal, including EEG) into a series of sinusoids. ...


3

Light absorption happens because of interaction of light with electrons (in a way) such that the energy of the light is transferred to some electrons that moves them to a higher energy state. As per quantum chemistry (Bohr's model of hydrogen can be referred for a basic understanding), there are distinct energy states (solutions of the Schrödinger equation)...


3

I think you are correct, but I'm not an expert in Diptera/Drosophila morphology. Since the prothorax (pronotum) and metathorax are greatly reduced in flies, you mostly see the mesonotum in dorsal view, and this includes the scutellum. Personally, I think it would have been more accurate of them to label this structure mesonotum, or at least dorsal mesothorax ...


3

Are you sure that your TBE is at the right dilution? And that you're using TBE to make the gel and also as the buffer for running? That sort of wavy line looks like what you might get if you'd made the gel with water instead of buffer, or run it with water instead of buffer. You could also try using TAE to make/run the gel as a sanity check.


3

NEB double digest planner is suggesting to use 2.1 buffer for your combination of restriction enzymes (XmaI 50% and KpnI 75% activity). I would be more worried about the star activity of KpnI in CutSmart buffer than the lower activity. The latter can be overcomed by prolonging reaction time or using more enzyme.


2

Yes sure I tried this and give good result. But you most chose the best protocol and need to be do this manually. I recommend that use CTAB-PVP (which is use 3 buffers EBA EBB SDS %10) extraction method from "Integrated DNA technologies" and if you cant find this I will tell You.


2

The placement in terms of location on the scalp determines what region of the brain is sampled. The electrode density determines how many locations are sampled. The spatial resolution of an EEG has been reported to be 7 mm (Im et al., 2006), meaning the variability in determined source and verified source (via fMRI in the study cited) is approximately 7 mm. ...


2

I came across a nice Master's thesis that investigated precisely that. The conclusion reads as follows: Automated microbroth dilution-based testing methods are increasingly used by many clinical microbiology laboratories to determinate antimicrobial susceptibility. Thus, it is vital that these methods are able to accurately determine the correct ...


2

In addendum, keeping the wavelength around the absorption maximum for the light-attenuating species avoids introducing error into Beer's Law. There are limitations to the law, outlined here where we can see that around the lambda max, there's little change in absorption per unit wavelength: In case B, this would end up returning a bad extinction coefficient!...


2

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 time means a cycle time of 20 ms. If light ON and OFF times are equal, then the ON and OFF times are both 10 ms each. Background The unit hertz (Hz) is a ...


2

This is a routine procedure in FPLC to prepare columns for storage. 20% ethanol is used to prevent microbial growth. See this technical note: All SEC columns are delivered in 20% ethanol to prevent microbial growth.


2

Assuming that by "discrete", you mean "discrete and ordinal" (like 2, 21, 7, 12) and not "discrete and nominal" (like red, blue, yellow, green), then it is really easy. It just mean you can just use your numbers. The contrast between lineage with average trait 6 and lineage with average trait 9, the contrast is therefore 3. If your data are nominal, then ...


2

Try going even higher with the agarose concentration, as it looks like you have decent separation of the small bands and poor separation of the large bands. Also try a fresh batch of agarose. I would suggest trying 2-4% in 0.5% steps If you are running 100bp or smaller fragments, you should in the range of 4% agarose. Here is a nice example of agarose ...


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