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23

In my experience it is very rare to see a protocol for humans that describes how to pipette a certain liquid, but I don't have as many years pipetting as others do. In general, it is left to the experimenter to observe the behavior of the liquid and act accordingly. It is quite easy to determine when a liquid is leaking (e.g. ethanol) or when it is very ...


23

I work on software that controls one model of robotic pipetter. There are a few reasons why we use complex liquid class definitions: One of the selling points of using a robot is high speed. You can handle a wide range of viscosities if you set a conservative (slow) speed for aspiration/dispense, but for solutions that don't require this, we'd like to be ...


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, ...


8

This is a lateral flow assay. [image source] A sample is applied at one end of the strip and flows across to the other side by capillary action. It first encounters antibodies against the target antigen and which are conjugated to some reporter (in the image above, the reporter is colloidal gold). When the sample contacts these antibodies, they too will ...


7

Just to be clear, it has been many years since I have done real lab work, so I am certainly not an expert on the specific question. However, I have a fair amount of experience writing clear instructions to cover complex (and often bespoke) processes. As Dan Bryant has explained, robotic systems absolutely need the additional detail in order to complete ...


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 ...


6

From a technical perspective, for the FlopR package you mention (and I believe also for Jacob Beal's protocol) you can simply change the bead size and perform a new calibration. The only information that you need is the bead count at each point of your calibrant curve. However, using calibration beads of a given size assumes that your cells will remain ...


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.


3

If you haven’t already ordered your enzyme, you could get high fidelity KpnI, which has been engineered for use in CutSmart. You could also consider doing a sequential digest rather than a double digest (ie digest with one enzyme in its optimal buffer then change the buffer for digestion with the second enzyme). It is more work but benefits from easier ...


3

In my experience, a double digestion in CutSmart buffer will work perfectly well. The reaction may proceed slower, but incubate it a little longer and run a gel after the digestion - you'll see whether it has worked. The other answerers unfortunately did not mention that the best way is to check the restriction products yourself on a gel. Cut out the ...


3

The term appears to be in use as a synonym. PLOS ONE is a good journal, and in it Okubo, 2016 write "The protocol for ISHH was described in detail previously [22]." Where [22] is Yamanaka, 2007, describing a classic ISH protocol. Note that both papers use good old fashioned nuclear tract emulsion for S-35 labelled probes. The ISHH protocol is in ...


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