Culturing your favorite ciliate: Paramecium busaria

It happens to all of us collectors. You find an interesting rock and you want to keep it in your pocket for further study. Many kids have pencil boxes and pockets full of bugs. In my case, I dream to have a large collection of ciliates, although I have had more failures than success in…

Coleps: The Piraña of the ciliates

One of the most deadly ciliates that can even take on larger predatory ciliates like Didinium is Coleps. These are barrel-shaped ciliates with characteristic plate-like structures. They often hunt in packs and clean up dead ciliates or weakened ones. I have been inadvertently growing Coleps, while studying interactions between Didinium (the T-Rex of the ciliate…

Rheinberg illumination for Foldscope

123 years ago Julius Rheinberg invented a variation of the darkfield microscope by adding color to it. Essentially it involved using various combinations of transparent colored papers set up in a way where diffracted light would be of one color and the direct light falling on the object of another. Typically annular rings are made…

Ciliate motion: Saltation and its possible reversal in Cyclidium

One aspect that strikes you when you look at microbial life is the range of types of motion. It is what brings out the oohs and aahs to people around you. Each type of motion is a product of finding a solution to the Reynold’s number problem (Its like swimming in jelly for these critter), escape…

Tetrahymena thermophila mutants: Fat, Mouthless and Balloon

Thanks to the wonderful ASSETT program, I had the opportunity to procure various temperature sensitive mutants of Tetrahymena thermophila. These grow normally at room temperature, but at 37℃ /98.6℉ they display defects due to mutations in genes involved in cell division (hence called temperature sensitive mutants). My first step in reproducing these phenotypes was to…

Bdelloid rotifer development

I have moved to a new kind of foldscope-inspired project– growing near pure cultures of microbes; ciliates, little animals etc. At the outset, let me confess that not one of my cultures has successfully propagated over the past 6 months or so. Wasted plates, contaminated media, complaints from other human residents of the house about…

Dressing up protozoans (Vital Staining): Tetrahymena Vorax Part 2

Have you ever tried to stain ciliates naively, i.e. without knowing any protocol, just adding methylene blue or some such dye? More than often all one sees are shriveled cells that don’t resemble anything like the live ones. For long, microscopists have used vital stains to stain ciliates live and I have always been wanting…

Polymorphism, cannibalism, epigenetics, and biological conflict: The many stories of Tetrahymena vorax – Part I

There are fascinating stories in biological systems and here is one I recently learnt thanks to the ASSETT program. https://tetrahymenaasset.vet.cornell.edu/science-modules/by-name/cannibalism-and-interspecific-predation/ Tetrahymena vorax is much larger than Tetrahymena thermophila. It also looks very different, swims more like a fish and very interestingly shows a great degree of polymorphisms in shape. As the resources in a growth…

Imaging Tetrahymena thermophila cilia

Tetrahymena thermophila are covered by about 21 rows cilia each with about 30 cilia. These 600 odd cilia allow it to propagate by beating in a coordinated way. The cilia also surround the oral apparatus to sweep food into it. These cilia are probably in the 1 micrometer range and hence imaging them requires one…

A simple hack for reflection/epi-illumination using the foldscope

I have been wanting to post on this for long. There is a very simple way to achieve reflection/epi-illumination microscopy in the new foldscope. For this, I use a simple LED hack that was described by Marie. See https://microcosmos.foldscope.com/?p=13486.  This LED unit can now be inserted from the side as seen in this video. The video…

ASSETT and Foldscope: A marriage made in microcosmos heaven

The past 6 weeks or so I have been tinkering with Tetrahymenas thanks to the wonderful ASSETT program run by Cornell University. ASSETT or Advancing Secondary Science Education through Tetrahymena is an NIH funded program that provides modular science education material for schools, using Tetrahymena as a model system.  Each module is well designed keeping the…

Exploring a Slime Mold-2: Tracks outside and within

Continuing from my previous post, you can imagine that all my free time is spent trying to do as much with the slime mold. By now I am quite certain that this is some kind of Fulgio species (perhaps Fulgio septica). However,one needs to really look for several traits before deciding the species, and so…

Polarized light foldscopy

I finally got myself a polarizing film. By this I can now polarize the light falling on the sample by placing the film between the light source and the sample and further by placing another film between the lens and the eye/camera I can block the same polarized light so that only light whose polarization…

Exploring a Slime Mold-1: Detection, isolation and culturing

Slime molds have fascinated me from childhood. I read about them in a library book and as an undergrad tried to culture them with little success (all I got were tracks of gnats).  The disappointment lasted many decades. A couple of years ago I got a sample of a slime mold from a friends’ porch,…

Surfing surfaces

Here is a hack with the new foldscope lens. Using a magnetic coupler and a lens, couple the two onto the phone’s camera-eye. This can be directly used to scan objects. For a reflecting light source, you can use the camera flashlight (if your app allows you to have the flashlight and the camera on…

Measuring the Foldscope Universe-1: Using the kit scale

In any scientific endeavor, measurements are a central aspect, and so I was delighted when I saw slide scales in the new foldscope kit. This meant that I could calibrate my phone camera with the slide scales. The smallest division on SLIDE A2 is 0.5 mm. Under the foldcsope at no digital zoom, that is…

Unboxing at midnight

Dark was the night and the date slipped over to the next. The wind howled as the critters froze under the million eyes of the crisp “Thanksgiving sky”.  But we were undeterred and bravely sneaked to the box, while the others slept in fear of the dark. Assembling the foldscope was a breeze, in spite…

Our Latex experiments

We wondered what the white latex of a Ficus plant would look like under a Foldscope. Here is the experiment in 5 short videos Video 1/5: Latex in Ficus elongatus.   Video 2/5. We spread the latex onto the slide. We had two slides, one in which we really stirred the latex and the other…

Insect larva before and after mounting in Karo

I brought home some pond water a couple of weeks ago, but in the summer heat, the water turned anaerobic (smelling of H2S) and I hastily took some of the smelly water and to my delight saw this larva. I think it is definitely some Dipteran species, although which one I am not sure. I love…

Biodiversity in a small drop of pondwater

Yesterday was Biodiversity day. Biodiversity is usually celebrated with pictures or collages of a wide range of animals and plants. To think that it is only about 1% of life on earth is mind-boggling.  We are so sensitive to extinctions of mammals, birds, insects and plants today thanks to a few remarkable individuals who have…

Day 7: Lichen culture– part 2

Continuing from my previous post, the April22-plate 3 was really remarkable. Without much ado, here is a sampling of what I saw. Looking forward to your feedback and also can you identify the mystery objects: 1. Nematode (Nematode-24728-1-LI): A fairly large nematode. You can see the pharynx and a bit of the digestive track. There…

Day 7: Lichen cultures

Continuing from my previous post, I am going to try and keep an eye on the succession of life in my lichen cultures. For this, I have 6 different lichens collected from different trees put into petridishes containing RO water. Below, I categorize all life I could see after 1 week. Here are results from three…

Lichen suspensions as growth media

For some time now, I have been completely bowled over with lichen suspensions (1,2,3). You never know what surprise you’d get. I suppose, it would be so for mosses too.  All I do is to drop a lichen scraping in a small petridish with about 5 ml of bottled water and follow it for days,…

Help me identify these ciliates and flagellates

Without much ado, here are 5 unicellular eukaryotes that were growing in my lichen suspensions. These emerged after almost 4 weeks. I took these videos at the beginning of the year,  and only now found time to collate them. Could you help me identify these? BTW, even after 4 months, I have nematodes and rotifers thriving…

A Lousy day and permanent slides

A few months ago, a young micronaut, Aditi, had a lice infestation on her hair and before subjecting her to the lice treatment we got a couple of the critters and foldscoped them.  Without much ado here are the  collated videos. One of the things I have been wanting to do is to make some permanent…

Foldscoop 1:3. Long-term Lichen suspensions

Laziness is a good thing; sometimes. Previously I had posted on observing tardigrades, ciliates and nematodes (1, 2)  in Lichens. It so happened that due to a hundred obstacles that life so often places, I  forgot to observe the lichens suspended in mineral water for about two weeks. By this point, the water turned dark brown…

Tardigrade and friends

I have been greatly inspired by the Stanford Tardigrade post and want to explore the local lichens for similar associations. Initially, I was just focused on finding Tardigrades, but then everytime I picked up a lichen for foldscoping there were other life forms that were consistently observed in the same environs. I then thought that I  should report…

Ecosystem networks and flux

Any species that we observe under a microscope is part of an ecological network that depends on resources and interactions with other species. Think of all the ecosystems we are so used to seeing and reading about regularly: Serengeti, Yosemite, Kaziranga, Madagascar and Artic, each of these have completely different profiles of macro-species from the…