Talk:Differential interference contrast microscopy

Synonym

I believe DIC is also known as Nomarski microscopy —The preceding unsigned comment was added by 129.67.129.15 (talk • contribs) 17:52, October 15, 2006 .

Indeed it is.--Srleffler 00:51, 16 October 2006 (UTC)

Already a while ago I created a redirection page: Nomarski interference contrast. Pvosta 19:14, 17 October 2006 (UTC)

At the NIC disambiguation page I (re-added) Nomarski Interference Contrast.~~

Example

This should have an actual DIC picture. —Ben FrantzDale 02:15, 13 November 2006 (UTC)

Photo added of yeast under DIC illumination. - Zephyris _Talk 11:21, 18 February 2007 (UTC)

Instruction Manual?

I recently adopted a DIC olympus microscope and don't really know how to use it optimally. I have read a basic book about microscopy, but it didn't include anything on DIC. I have the instruction manual from olympus but that just includes how to line things up and set up the scope, not how to get the best use from it.

I was just wondering if anybody had a good source about the fundamentals of the scope that could be added so I, and others, could learn a bit about it. Preferably a PDF. Thanks a lot, Rjkd12 16:21, 22 January 2007 (UTC)

http://www.microscopyu.com/articles/dic/dicindex.html and http://microscopy.berkeley.edu/Resources/instruction/DIC.html may be useful... have a read of these - Zephyris _Talk 11:21, 18 February 2007 (UTC)

DIC vs Phase Contrast, and AVEC-DIC

Everyone always says DIC looks better than phase, but on my main microscope (a Nikon Eclipse TE-2000U, using 60x objectives), i don't find that. I think we have abnormally good phase contrast, for some reason!

Anyway, concerning the article, a disadvantage of DIC compared to phase that i've heard is that DIC optics are more demanding in terms of alignment and adjustment; phase is something any lummox can make work on their random tissue culture room microscope, but DIC takes some finesse (possibly the reason it doesn't look so great on my scope!). Is there any basis to that? If so, we should mention it and give details.

Also, a minor thing perhaps, but a big difference between phase and DIC systems is the optical efficiency; you need to put far less light into a DIC than a phase system to get comparable brightness at your eye, and moreover, far less light onto the sample, which is good news for live cell imaging. Related to this is the fact that DIC lenses are also more efficient (do we say 'faster' for microscope lenses?) for fluorescence imaging, so if you have a setup oriented towards fluorescence, going for DIC as your transmission method is a wise move.

Lastly, there's a technique called AVEC-DIC (the 'VEC' bit is, i think,'video enhanced contrast') which was quite popular with fancy-pants microscopists in the '80s, before fluorescence imaging of live cells became feasible, that somehow gives even better images than DIC; i have a 1988 paper by Colin Izzard where he uses it to look at forming actin bundles in migrating cells, something i struggle to do with GFP-actin and hojillions of pounds' worth of confocal microscope.

(edit: we have an entry under vedic for video-enhanced DIC, which just points here, where there isn't an explanation; we do have a citation down at the bottom, though; i should read up on this and come back and write about it)

-- Tom Anderson 2007-02-20 1345 +0000

Good comments!

• DIC optics are both more expensive and more complex than phase, and so almost certainly harder to set up. I think this belongs in the article if true.
• For optical efficiency do you have a good reference for this? I like this as a concept, and again it belongs in the article.
• Let us know about AVEC-DIC!

- Zephyris _Talk 17:10, 20 February 2007 (UTC)

Image: The route of light througn a DIC microscope.

The image "The route of light througn a DIC microscope" is wrong - The light path is unphysical and DIC does not work this way... (why should a beam change its direction if it is orthogonal to the surface) PLS change! BTW - There is a spelling error in the title (The route of light througn a DIC microscope). --BoP (talk) 08:04, 17 September 2008 (UTC)

There is a lot of disagreement about how the rays refract through these prisms out there if you search on the net. For example, the following pages indicate that the light should show no refraction until it reaches the tilted interfaces between the prisms (https://www.olympus-lifescience.com/ja/microscope-resource/primer/techniques/dic/dicintro/ and also https://www.olympus-lifescience.com/en/microscope-resource/primer/techniques/dic/dicoverview/). However, these pages clearly show that the prisms are not Nomarski prisms but rather Wollaston prisms. As the Wikipedia page on Nomarski prisms (https://en.wikipedia.org/wiki/Nomarski_prism) clearly shows, an incoming ray orthogonal to the surface still experiences refraction, undoubtedly because the two polarization directions both have components along the extraordinary refractive index axis of the crystal, and the extraordinary index does not obey Snell's law. Also, the figure labels on the image here say that the prisms are Wollaston prisms, but the figure clearly shows that these are Nomarski prisms. So, to sum up: the rays shown here are reasonable approximations for a Nomarski prism pair, but not for a Wollaston pair. NH (talk) 02:37, 5 October 2020 (UTC)

Yes. As mentioned at Birefringence § Double refraction, when the optic axis of the crystal is neither parallel to nor perpendicular to the surface, you can get refraction even at normal incidence. This is true in a Nomarski prism, but not in a Wollaston one.--Srleffler (talk) 01:34, 6 October 2020 (UTC)

Picture

Your pic of DIC has likely GFP markers (green) and therefore is not a true pure DIC/Nomarski image. You can do better. Never posted here before but I am a microscopist. Change it. — Preceding unsigned comment added by 174.51.94.31 (talk) 06:13, 16 February 2012 (UTC)

It would be nice to have one that is not a composite. Do you have something you can donate, a the DIC image for some widefield fluorescent microscopy could be added here, showing the DIC image and the fluorescent channels, then the composite. Pseudofusulina (talk) 06:30, 16 February 2012 (UTC)

Advantages and disadvantages is a bunch of junk

I read the advantages and disadvantages section and it looks wrong. I think the author should say DIC is better than XXX for the following application. Can we please get rid of it? It looks like misinformation to me. --Frozenport (talk) 02:36, 3 April 2016 (UTC)

Picture

What is the purpose of this Differential_interference_contrast_microscopy#/media/File:Laser-Induced_Optical_Damage_in_LiNbO3.jpg Laser-induced optical damage in LiNbO3 under 150× Nomarski microscopy picture? Example DIC image? When I initially read the caption I thought it was damage caused by DIC with laser. — Preceding unsigned comment added by 128.112.217.158 (talk) 22:04, 7 February 2017 (UTC)

It's an example DIC image, looking at laser damage on a surface.--Srleffler (talk) 05:35, 16 February 2017 (UTC)

some limits which should be known

DIC doesn't works with plastic dishes/wellplates etc. the plastics disturbes the polarisation.

In this case, the Hoffmann Contrast is the better choice, because this contrast method works with plastic dishes. The Hoffmann Contrast (eg. Olympus Relief Contrast) is often used in IVF.

The Result of Hoffmann Contrast is not as good as DIC, but the equipment is cheaper and it works with plasticdishes.

More pictures from biology

It would help if some more images could be added from biology. For example, I was looking today at this wikipedia entry to get more information how certain animal cells look under the DIC, due to a contamination we had locally. Thus, any more picture here may be of help; right now there are only perhaps 1-2 pictures from biology or so on the DIC page, give or take. 2A02:8388:1641:8380:8920:7EEB:D50A:6466 (talk) 21:45, 22 October 2019 (UTC)