Differential Interference Contrast Observation of Transparent Samples Using an HDD Platter with a Metallurgical Microscope — Introducing the HDD Platter Holder

 In a previous article, I introduced a method for differential interference contrast (DIC) observation using HDD platters under epi-illumination. For more detailed information on observing transparent samples with epi-illumination, I recommend referring to specialized literature (in Japanese).

This time, I’d like to introduce a method for handling samples using HDD platters.

HDD platters are circular disks approximately 10 cm in diameter, which makes them unsuitable for direct placement on a standard microscope stage. To address this, I designed a custom tray that can hold an HDD platter securely. The tray is removable, so you can place the HDD platter onto it outside of the microscope and then easily transfer it onto the stage.

Besides HDD platters, the tray can also accommodate petri dishes, or you can place samples directly on the tray surface for observation. I find this tray to be quite convenient when working with a metallurgical microscope.

If there’s enough interest, I’m considering making this tray available for purchase. If you’re interested, please feel free to contact me via the contact form.

I understand that not many people have HDD platters lying around, but I do have a few available if needed—please inquire for details. I do regret throwing away dozens of old hard drives when I moved!

This novie shows a comparison between darkfield observation and differential interference contrast (DIC) observation of Stentor (trumpet-shaped protozoa) using a metallurgical microscope. The DIC image taken with the aid of an HDD platter closely resembles what you would typically see with transmitted light DIC.

To prepare the sample, a vinyl tape rim was created on the HDD platter to form a shallow well.

The sample was placed inside, sealed with a cover glass, and the platter was then mounted onto the custom tray.

The tray is attached to the microscope stage and held in place magnetically.

It allows smooth movement in the XY directions, just like with standard observations.

The reflected light illuminator shown in the photo is a prototype of a new model. Some of the components previously used for the BH2 UMA's reflected illumination system have become unavailable, so a new illuminator is being developed using currently obtainable parts. It’s expected to be completed within a week.