11 votes
Accepted

Why is there a λ⁴ in the spectral overlap integral in FRET calculations

Why this is such a good question After finishing teaching at 8pm EDT, it took me about 1 hour to find the answer and 1.5 hours writing this answer and confirming things. The Wikipedia article just ...
user1271772's user avatar
11 votes
Accepted

Why are microtubules absent in and around the nucleus?

tl;dr Cells are 3D and the cytoskeleton does not exist within the nucleus. There are several things you have to be aware of when looking at such pictures. Remember, you are looking at a 3D object ...
S Pr's user avatar
  • 6,222
8 votes
Accepted

is it possible to visualize coronavirus infection and what type of assays are routinely used?

If you have an antibody against the viral proteins you can do an immuno staining followed by fluorescence imaging. For this type of technique you would need a very specific antibody. I am not aware ...
Dr. H. Lecter's user avatar
7 votes
Accepted

Is colocalisation of a protein with a presynaptic marker sufficient evidence to say that the protein is a component of axon terminals?

Colocalization of a protein with another structure is necessary but not sufficient to say that the protein is a component of that structure. Mixed into the concept of a structure's existence is the ...
Ryan's user avatar
  • 1,311
6 votes
Accepted

Suggestion on program/algorithm to segment nuclei

The "Analyze Particles" function in FIJI might work. You will run into a few problems in any entirely automated analysis because your image isn't even brightness across the image; the ...
bob1's user avatar
  • 12.1k
6 votes
Accepted

In fluorescence microscopy images what is meant by the term "puncta"?

I have read that the general definition for puncta is a small, distinct point. That's correct. From my understanding, puncta are dots. However, I was wondering whether puncta is a synonym for ...
acvill's user avatar
  • 8,296
5 votes

Is colocalisation of a protein with a presynaptic marker sufficient evidence to say that the protein is a component of axon terminals?

Empirical science is not based on proof, but on evidence. No one study is the final word on anything. "Sufficient evidence" is entirely up to the person operating on the evidence and what ...
Bryan Krause's user avatar
  • 45.7k
3 votes
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Are antibodies labelled with fluorescence that have not attached to an antigen visible under light microsocopes?

By far the most common IHC protocol, in my experience, is using a primary antibody which binds to your target of interest, followed by a secondary antibody (which carries the fluorescent tag or ...
Bryan Krause's user avatar
  • 45.7k
3 votes
Accepted

How to measure the pH of a bacterial species?

The pH level of the Bacterial Intracellular structure is different from the pH level on the eternal side of the cell. Moreover, there are no studies that suggest that a change in the external pH of ...
Anwar Elhadad's user avatar
3 votes
Accepted

What does it mean to "cure" microscope slides?

In this context, "cure" is a chemical term. Definition from Wikipedia : Curing is a chemical process employed in polymer chemistry and process engineering that produces the toughening or ...
GaelC's user avatar
  • 466
3 votes

Does the use of UV light beam lead to poorer contrast in optical microscopy of cells than the higher wavelengths visible light?

Contrast in optical microscopy typically depends on different substances having different absorption spectra. Practically everything absorbs UV light, so there tends to be less contrast in that range ...
S. McGrew's user avatar
  • 737
3 votes
Accepted

Is NADH found in all type of cell in human body?

As NAD+/NADH is involved in both glycolysis and in the tricarboxylic acid cycle it is difficult to imagine any cell capable of generating energy not having some NADH. (Are there any cells that are not ...
David's user avatar
  • 25.7k
2 votes
Accepted

How are light sheet microscopy 3D images and their computed sections built up from stacks of 2D images?

According to their website dispim.org they are using registration software like the ImageJ Multiview-Reconstruction Plugin. Judging from the descriptions, this plugin uses the alignment of multiple ...
Frieke's user avatar
  • 1,127
2 votes

Need help with ImageJ thresholding

Check the "dark background" checkbox that is unchecked if the background is dark and you want to select the bright cells. Right now it is assuming the background is bright.
Bryan Krause's user avatar
  • 45.7k
2 votes

colocalization by IFA?

If you search the web or Google Scholar, you should be able to find plenty of examples of colocalization protocols. In general, though, for each target you're going to want to have an unstained ...
MattDMo's user avatar
  • 15.3k
2 votes

Can Ni-NTA-Atto Conjugates bind to single His-tag

According to the unreferenced introduction to Wikipedia's article on poly-histidine tags, the number of His residues can vary from two to ten, with six being the most common. Since histidine is a ...
MattDMo's user avatar
  • 15.3k
1 vote

What is the process by which fluorescent proteins in two photon microscopy are optically stimulated by membrane depolarization?

They are using a GCaMP, specifically GCaMP6s and GCaMP6f. This is a genetically encoded sensor. Cells expressing the gene make a protein. The protein is inside the cell, in the cytoplasm. This protein ...
Bryan Krause's user avatar
  • 45.7k
1 vote

Why are microtubules absent in and around the nucleus?

@MasterOfGalaxy one of the roles of the microtubule cytoskeleton is the mechanical support of the cell. The nucleus has its own specific skeleton. The nuclear lamina is a proteinaceous meshwork ...
Arash Salehi's user avatar
1 vote
Accepted

How does Line Integrate work on a laser scanning confocal microscope?

Most microscope software provides options for line average or line integrate as a function that helps the signal to noise ratio when taking an image. Averaging sums the lines and then divides by the ...
user1850479's user avatar
1 vote
Accepted

Quick overview of how to capture microscope images of histology plate or fluorescent plate

For fluorescent microscopy images, wondering if I actually need a fluorescent microscope, or if I can make do with a regular optical microscope. You need a fluorescence microscope. You need to be ...
S Pr's user avatar
  • 6,222
1 vote

How to measure the length of mitochondria from z stack fluorescent microscopy image?

ImageJ is usually the standard software to measure cell characteristics, a little bit of a learning curve but there is a large suite of analysis methods and image adjustments/filters.
Tom V.'s user avatar
  • 321
1 vote
Accepted

Possible to remove accumulated haze on fluorescence interference filters?

In fact, filters can be damaged by heat. However, newer filter coatings are less prone to heat damage [details]. For the barrier filter, it's less likely to be heat damage. The older/less expensive ...
TSwayne's user avatar
  • 221
1 vote

How to choose right volume of DNA and SYBR Green

I had to look it up online, but I eventually found here an important information: the detection limits of SYBR Green. dsDNA at 300nm transillumination: 60 pg Oligonucleotides at 300nm ...
Guillaume's user avatar
  • 715
1 vote

Can streptavidin be conjugated with EDC-activated carboxylates?

The EDC-activated carboxylate is actually positively charged, though I cannot speak to the density of carboxylates in your hydrogel or the extent of activation with your protocol. Subsequent NHS ...
canadianer's user avatar
  • 17.7k
1 vote

Combination of different antibodies

If they are made in different animals you should be fine. You could do a western with those antibodies though, to double-check. Looks like Cenp-C is about 106kD and Rod1 is about 60kD. So on a ...
mykinz's user avatar
  • 41

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