Microscopy Definition and 54 Threads

I am trying to align two ~100-140 fs pulsed lasers, one at 1040 nm and one between 750-950 nm through a working custom 2p microscope. The end goal is to do stimulated Raman (CARS and SRS) which requires the two beams to be coincident and the pulses to be perfectly synchronized in time, however...

In optical microscope both objective and eyepiece are used to magnify the sample image. Magnification is determined by laws of geometrical optics (intersection of optical beams from the same point of the sample) In electron microscope, electromagnetic lenses are used to magnify the sample...

Hello, If I understand it correctly, the samples are grounded inside a scanning electron microscope (SEM) to avoid charge build up through the electron beam. Also the non-conductive are coated with a conductive layer, so they can be grounded as well. However, I do not know how the charge build...

We know the RT-PCR test method currently employed to detect SARS-CoV2 viruses from the sample is not 100% foolproof in detection. If the current electron microscopy can reach a resolution of up to 50pm, why not use this time-tested technology in the detection of this virus? Are there any...

I'm aware that GFP tagged protein can be visualized under fluorescent microscopy. I don't know if it is possible with fluorescent tagged antibodies also. I did some research but couldn't find any information about this. The answer provided is no. (pg 25, sum no.142)

I have been looking online and it is stated to be 1nm, but these are posts around 6 years old: https://www.azonano.com/article.aspx?ArticleID=3662 https://www.researchgate.net/post/Whats_the_measurement_limit_of_dynamic_light_scattering I am wondering if the limiting resolution has improved...

I am studying the modes of operation of the Atomic Force Microscopy (AFM). I know there are three: contact, tapping and non-contact. Are they really used in both hard and soft matter physics? If so, how are the difficulties/limitations that they present overcome?

What are the different signals we obtain from TEM and How can we distinguish between them? what are the significances of those signals?

Hello, I'm having trouble understanding how and why the math is the way that it is to get the answer. The question states: A specimen has a diameter of 1.5 micrometer. What is the minimum magnification that will allow a human to resolve this object? 150 micrometer/1.5 micrometer = 100X <--...

I came across your site while looking for information on how to advance our ability to view beyond the capabilities of current electron microscopy technology. I do not know where to start asking but I hoped you could point me in the right direction. I’m about to enroll in university classes and...

Hi. I'm a retired several-sciences guy, a STEM Ambassador encouraging kids to look at science, hopefully fostering interest. I'm also interested in microscopy. I/we are looking for ideas for small items which demonstrate interesting/educational things, for kids to look at through microscopes...

I know localisation microscopy 'beats' the limit on resolution by activating individual sources and rendering a final image, but what are the limits that prevent the resolution of the images of these individual fluorophores? Is it just the number of photons collected? Cheers

I want to ask the limits on the molecule side for single molecule fluorescence microscopy. I am writing a proposal but I lack experimental knowledge since no one in my lab have ever used one. At least how much of an absorption coefficient, with at least how much of a radiative rate is necessary...

Hello folks, There is a wide variety of techniques to measure at the nanoscale. There are Scanning Electron Microscopes, Scanning Transmission Microscopes, Scanning Force Microscopes, STM... Also there are several devices used to analyze the Spectra of atoms: XPS, AES, UPS, HREELS... I...

I was wondering if someone could offer an explanation as to why TEMs and SEMs have practical resolutions several orders of magnitude less than what is predicted by the Rayleigh Criterion. This of course comes from my own calculations of the Rayleigh Criterion assuming an electron is accelerated...

I have been researching wave/particle duality, and I have trouble comprehending how electron microscopy actually exploits wave/particle duality to operate. From Wikipedia, " Wave–particle duality is exploited in electron microscopy, where the small wavelengths associated with the electron can...

I found this interesting computer animation representing DNA functions in cells. My questions: 1) How precisely can we actually magnify cell functions, and what is preventing us from peering in as closely as depicted in the video (keeping in mind that I know it's probably technologically...

Hi all, If a camera images a fluorescent molecule gaussian function with diameter roughly 300nm and each image pixel represents 160x160nm how could you say with higher precision where the molecule is located within that pixel. For instance if the localisation precision turns out to be 40nm how...

How one can analyse an image of a solid material obtained with an optical microscope ?

I'm looking for a quick and well synthetized reference to the TEM technique. I'm writing a monography, we used TEM on a sample (just sended it to the lab, I dind't do the work). I don't have any reference, and I wanted to give a kind of introduction in the monography to TEM. I don't want a whole...

If you're using a phase contrast microscope and the refractive index of the medium is equal to the refractive index of the cell, what are you able to see? I guessed that you wouldn't see anything, but apparently that's wrong. The only options are membranes, vesicles, the nucleus, pigment...

Okay so first I would like someone to add detail to my descriptions of different types of light microscopy. Here's what I know: Brightfield (unstained): standard view of partially opaque, live cells. Brightfield (stained): standard view of colored, dead cells. Phase Contrast: Not sure how it...

https://www.dropbox.com/sc/eo2c8j4kd12pdvn/AACGJ8YZvk35BSX1BsBoKIIsa Please view the above image. I am getting awesome contrast on the periphery of the image but hardly any in the center. The sample is an H and E stained tissue and I just got the microscope in today. I am a rookie with...

Looking at Ben Krasnow's youtube video on breaking down the parts and general cost for a scanning electron microscope, he lists a raster scan generator, is that able to produce the highest resolution images still? Or is there another more modern technology for this purpose? Otherwise, how has...

In fluorescence microscopy, dichroic mirrors reflect light under a critical wavelength (used to excite the sample) and transmit light over a critical wavelength (emission light from the sample). Are there mirrors that reflect two different wavelengths of light and transmit the rest? Essentially...

My question is simple: Why do the Fresnel fringes at the edge of a hole in a reticulated carbon film become larger and more widely spaced when the defocus is increased? This occurs whether you are over focused or under focused, right? But why?

What is an advantage of using matter wavelengths over light wavelengths for microscopy? Why to use electron microscopy if one can use X-rays in a range of angstroms. Thank you.

I can only find micrographs (photographs of microstructure under electron microscope) of non-transparent glasses. Is it impossible top be able to see the internal structure of a transparent material? If anyone can tell me what I'm doing wrong or find me one that would be great! I'm looking...

Hi all, In a diffracted limited microscope the resolution has a limit given by the Airy disk and this gives rise to the Rayleigh criteria. But if I deconvolve the observed image removing the psf then I eliminate the diffraction effects and I can resolve any distinct points, whatever close they...

In several fiber-optic-based probes in medical imaging fields, the light travels towards an object through an optical fiber (or even free space), interacts with the object and then travels back through the same fiber (or the same path in free space) and is captured by a camera or photodetector...

I have been reading up on PALM works and am still confused about a few things. In particular, (1) how can you only excite a few molecules at a time and then only photobleach those molecules? Won't other molecules also automatically be excited and eventually photobleached? (2) When you fit the...

Hi all, My question concerns the theory of how super resolution microscopy causes a frequency shift to allow information normally outside of the observable region of frequency space to be captured by the objective lens. I have read various papers on this including those by Mats Gustafsson...

Hi all, I have a question about airy patterns and how these determine resolution in images. So to increase resolution the airy pattern should be made smaller. In microscopy this is achieved by using higher numerical aperture lenses and shorter wavelengths. I have also read that the more...

I have a question about observing a field of radiated light (and it's source) through a microscope, specifically vis magnification and the scale of the final image observed (the field, and also the source). I have a slice of field intensity at the plane of a microscope's numerical aperture...

Hi Everyone, I have recently made some graphene on copper via a chemical vapour deposition process. I have also managed to have a peep under an SEM at this. I do see what I believe to be monolayer graphene. I am very sure the contrast I see is graphene due to the growth patterns, ranging from...

Problem with opticalmicroscopy of features near vertical sidewall of very deep trench Hi, I posted my question here: physicsforums.com/showthread.php?t=612780 but there may be more specialists here. Essentially I have a feature right next to a very deep vertical sidewall of the deep...

I have recently started using an AFM machine, and have some issues with the way it saves the data. The people who maintain the machine haven't been very helpful with my concerns, so I'm hoping somebody here might be able to help me. I have been using Gwyddion to display the raw data images...

Folks, I'm self-taught and am currently trying to get up to date about the newest developments in field-emission microscopy and other methods of imaging sub-atomic structures. I'm able to follow (though just barely) Mikhailovskij et al.'s 2009 paper in Physical Review showing electron orbitals...

what is the depth of field of a microscope and how is it different from the depth of focus of the microscope.

I have a question about different microscopy techniques. What is major factor in determining a microscope's lateral and axial resolution for these three types: Confocal Multiphoton OCT The questions says to choose between wavelength, beam diameter, spot size, focal length, and depth of focus...

Hey all, Let me start off by saying that I am not a biologist, hence the ignorance of my questions! :eek: Basically, I'm wondering what are some common fixation agents used in optical microscopy? Specifically, I'm interested in looking at unstained epithelial cells. The most "advanced"...

I am a university student and have this question for you guys. Why do dead cells under phase contrast microscope do not show a bright halo? Thanks for your help Gen.hope55

Hello, My question is regarding sample preparation of biofilm for raman microscopy. In the past, I have used a Renishaw system 2000 raman spectrometer to study protein secondary structure. The sample preparation for this was fairly simple as I lyophilized the protein and placed it on a glass...

Hi I have a tutorial problem involving determining the ideal methods for identifying material properties of a layered semiconductor structure. The problem states to use either scanning or transmission electron microscopy. THe structure consists of several monolayers (around 5nm) of AlGaAs...

Hi I am trying to run a FRAP (fluorescence recovery after photo-bleaching) experiment but I am struggling a little bit. For those not exposed to the technique it involves, for example, bleaching a spot in a specimen that is fluorescing rendering that spot dark in contrast. I have two separate...

I've recently started trying to use this technique, but I've had some difficulties I can't figure out how to overcome. We make our own probe tips from a very small length of 30 gauge wire, and they seem to be of decent quality. We've tried to image a layer of graphite, a gold surface...

Homework Statement Hello! The question is as follows: 1. You are provided with a 1 cm3 of biological sample from which 0.1 mm thin sections are cut. A search for virus cells at a magnification of 100,000 has been proposed. The fluorescent screen on which the image is to be projected...

how to determine the resolution power of it? has it got anything to do with correlation wavelength? just wondering how it is calculated?

What gives raise to contrast in bright field microscopy, except shadows, pits and scratches?

What's the best way to hold a sample of micron-sized polystyrene beads for raman microscopy?