Preventing Objective Lens Damage: Blunt Force Trauma

This video describes the different ways objective lenses may be inadvertently scratched or cracked while using a microscope, and how to prevent these types of damage from occurring.

Video created by Jennifer Waters, Director of the Nikon Imaging Center at Harvard Medical School, with helpful suggestions from Anna Jost, Talley Lambert, Michael Weber & George Campbell.

References on cleaning objective lenses:
Petrak & Waters, A practical guide to microscope care and maintenance
DOI: 10.1016/B978-0-12-420138-5.00004-5
Inoue & Spring, Video Microscopy Chapter 3.3.4 - Inspecting and cleaning the optics and video camera faceplate
DOI: 10.1002/cyto.990080414

[amribrahim]

This Minicourses series are indispensable for microscopes users, particularly for beginners. I'm genuinely grateful for this series being created and looking forward to watch more.

[sharadatilve]

As someone who trains users in the core to use scopes I try and emphasize on the risk of objective damage. This video gave me great new talking points. Thank you :)

[marcomarcello]

Great video, and an invaluable help for facilities during the COVID time in 2020. Thanks Jennifer!

[DP-qbzw]

I covered the bottom of my stage petri dish holder with tape so the objective would hit a softer surface if accidentally touching it, plus, it is not fixed to the stage, so it can lift up, too, if touched by the objectives. But, best practice is lowering objectives before changing them.

[tymothylim]

This is very helpful! I learnt a lot from these videos!

[jonathanvaucher]

I purchase a used Zeiss Axioskop 20 and refitted it with Plan-Apochromat DRY objectives. I've always wondered: when you do need to clean an objective lens, what's softest and most appropriate solvent to use (talking about the usual dirt to remove here, not oil, mounting medium or any other special circumstances)? I've seen people use ethanol, methanol, n-hexanes, water from breathing onto the lens, anionic detergents, isopropyl alcohol, Dazzlens solution (i-PrOH and AcOH), pharmacy grade 70% rubbing alcohol... I really need your expert input on this. Is it better to use medical grade cotton swab damped in that solvent or wet lense paper to clean them ? How do you then dry them, dry cotton swab pass or dry lense paper pass ? Plan-apos are fine optics, I really want to prolong their life as much as possible... Thanks in advance for any advice.

[elpado]

Really interesting video thanks! However I think that breaking the cover slip for a non experienced user might be close to unavoidable. To move away is a good advice, but the problem is with the starting point. You say to move very close for oil immersion, but that "very close" is quite subjective and there is no way for a non experienced user to understand how close the objective is except for gently touching the cover slip. Especially when it is taking a long time to find the focal plane. I think one good advice is to keep the cover slip free to move away from the objective (at least with inverted microscope) in order to see that it gets pushed up when objective is touching. The other way to understand how close the objective is to look at how the oil is spreading and how it gets squeezed. But again that also takes experience.

[caraboutte]

This is so helpful, thanks! One question though, isn't it the stage that moves, instead of the nosepiece/objectives, during focusing?

[minicorefacility]

Thanks for the video, I have just embedded this video to my instrument blog which I take full responsibility for both inverted and upright microscopes.

[SuperSerNiko]

I believe some people just shouldn't use a microscope

[WastedElephant]

On my regular old compound microscope, I would love to only move the high power lenses away from the slide when focusing. The problem is that I am unable to see the tiny distance from the the slide to the lens. This means I can't safely bring the lens to the slide in order to move it only away while focusing. 🫤