MicrobeHunter.com Microscopy Forum

Plan 40x/0.65, DIC, 180µm, 3 stack stitch in Photoshop
Pinned by cover slip. Cleaned up background

Yet another amazing image 75RR

Yep, that's a breathtaking DIC effect alright! Amazing!!

It's doubly wonderful for me since I have the same optics on my bench, what better inspiration than that?

Bonjour
Superbe image en DIC.
Bravo pour votre travail que j'apprécie.
Cordialement seb

Many thanks Grahame, KurtM and vasselle. Very kind.

75RR wrote:Plan 40x/0.65, DIC, 180µm,
Pinned by cover slip.

When you say 'pinned' 75, do you imply you squeezed the slip down to sort of immobilize the copepod? I washed some slides last week and there must have been a residue of detergent left on them because the water sample spread very thin even before I placed the slip on. It didn't seem to kill my subjects but they certainly would have had less room to move around in.

When you say 'pinned' 75, do you imply you squeezed the slip down to sort of immobilize the copepod?

I use it to mean that the subject, in this case the copepod, is held down by the weight of the cover slip.
This will occur naturally via evaporation, provided there is not some detritus to hold the cover slip up.
One can accelerate the process using absorbent paper held to the edges of the cover slip or as you say pressing down on it.
However, pressing the cover slip down is a delicate business, as it is hard to gauge how much pressure to apply.
On the other hand two dimensional subjects are easier to photograph. ;)

A pinned subject can be released by adding a drop of water to the edge of the cover slip.
This is useful if the position it was pinned in was not ideal and we want to make another attempt or when we want to extend the viewing time of the wet slide.

Additionally, the higher the magnification of the objective the shallower the depth of field and the smaller the working distance, so with high power objectives, the less water between the subject and the cover slip the better. See tables:

Sorry - double post

That's quite a jump in DOF between 40x and 20x, the two objectives I use the most, and explains why my view at the higher power is diminished in terms of focus. Thanks for the tips on adding and removing water.