Vorticella slowed by a strobe light

[Chas]

Dug out an old strobe light

[youtube]https://youtu.be/1t8wKTbJoLg[/youtube]

For the first two thirds of the video it is going backwards, I think.

[Martin Parnham]

Hi Chas
Excellent video - fascinating, would you know what frequency your light was strobing at?
Martin

[Chas]

About 15 flashes per second.
The camera's video frame rate had to be adjusted to roughly match the strobe otherwise the resulting video flickered:

[youtube]https://youtu.be/9Tbc-8_ns-M[/youtube]

That was done using the MagicLantern firmware's 'FPS override'.

Once the camera's frame rate is set to a nearly correct rate, then the strobe has to be adjusted to match this or there is a sort of black curtain that slowly creeps up or down over the image.

[Chas]

That seems to have benefitted from lots of beginer's luck... it has been impossible to match the camera's frame rate with the strobe and to a vorticella this morning

Here is a zoom in of the first video that has been reversed to run in the direction that, I guess, is the correct one:

[youtube]https://youtu.be/XwJLGHn2eTQ[/youtube]

[Martin Parnham]

Sorry to here that Chas - Never the less that video was spot on. You have inspired me to have a go, and I now have some idea of the required frequency range for the strobe.

Thank you
Martin

[ddy5]

Wow - that is very cool! What a great idea! It's fascinating to watch the cilia in slow motion.

We used to use the old General Radio strobes that have variable rates and extremely short flashes to study insect wing motion in an undergraduate lab course. As with your Vorticella, the strobes provided a fascinating view of the repetitive motion. We saw the same kind of reversal effects you saw, which in that case simply had to do with the flash rate relative to a wing beat frequency that varied slightly from moment to moment. We didn't try videotaping, however. It sounds like a real challenge.

Cheers, David

[MichaelG.]

Excellent demonstration, Chas

… great potential for further studies.

MichaelG.

[Chas]

… great potential for further studies.

Yes, I think it would be really nice if someone with a DIC setup could get this to work.

We used to use the old General Radio strobes

I reckon the Xenon strobe that I used (a Dawe 1209c) might be from the same era as a GR 'Robotac' those look really great ..sadly my strobe is failing and also giving me little 'nips'
( I found an advert for the Dawe, from when it was released (1970), which claims it has a 5-10 microsecond flash duration) .

I have a different make of old xenon strobe coming from ebay ..but it looks to be more of a 'schools' model, so I guess it might have a longer flash duration.

I wonder if USB eyepiece cameras might have a continuously variable frame rate via the software(??)... if this is the case it might make things a little bit simpler.

[ddy5]

Chas - Just sent you a PM.

[charlie g]

Thanks for this great ciliate video, Chas. In human oral healthcare, current experimentation with different wavelengths of light spectrum...to promote better tissue healing after tooth extractions/ graft introductions to the traumatized jaw sockets, to promote tissue healing after soft tissue grafts over wounded sites. etc. tissue manipulations responding to specific wavelengths of light.

Long story short...mitochondria in human oral tissues absorb specific range of the light spectrum to manifest an enhancement in their metabolic output in healing mouth tissues.

I applaud your shared video...I cheer you to consider illuminating your target ciliates..strobe light set at different ranges of our light spectrum! You may search/repeat document, the response of how that ciliates 'metachronal beat frequency' responds to different spectral light ranges. Human mitochondrial cell organelles can't be the only mitochondria which react robustly to specific light spectrum range.

Thanks for a great microscopy video, I love pondlife wetmount microscopy. charlie guevara