Mounting algae in fructose syrup
Posted: Wed Dec 18, 2019 10:15 pm
I once thought about making semi-permanent slides (to last years, not decades) of algae without fixing and/or staining. Motivated by W. Dioni's published methods, I prepared fructose syrup from supermarket-grade fructose. About 80% (w/v) sugar, it is viscous and tends to include air bubbles and retain bubbles released among the plant leaves and stems. I fought bubbles with vacuum and other tricks, but when they are few in number, let them live. The syrup keeps very well at room temperature without mold or discoloration.
The following are images of three types of marine algae - two forms (A, B) of green filamentous and one (C) of green "leaves" from which green and red fibers tufts emerge. Sorry, no ID of any...
Alga A was mounted with glycerol and fructose syrup. Algae B and C - with syrup only. Algae samples were rinsed with distilled water, placed on the slide, excess water was removed with a piece of filter paper, covered with a slip, out-of-the-rims mountant was carefully removed with a wet Q-tip and finally, the sample was sealed with nail polish. Slides were stored in a box on a shelf at home, mostly at a temperature of 25-30C, and humidity 50-75%, without special precautions. The alga A slides are now 2.5 years old, the B and C slides are about two months old.
Brightfield images were obtained with a Plan 16X0.32 objective. All of them were taken with the same illumination and camera sensor ISO. All were referenced to the same white balance. In all images, the contrast and brightness were intensified by 50 and 70% respectively. They were also uniformly resized and cropped. No specific manipulation of colors was done. Each photo is a stack of 4-5 single images.
Unfortunately, background brightness is not uniform across the FOV, because of incompletely aligned somewhat illumination. Yet, the main point is how the mountant preformed. It would have been better to photograph the fresh algae in water, prior to mounting, as a reference of the colors, cell structure, cell size etc, for the future, but I failed to do so in time...; I also note that the syrup has an osmotic pressure, that in principle might affect plant cells some; nevertheless, the present images, at least, suggest the potential of fructose syrup to preserve alga pigments.
As always, comments are welcome.
The following are images of three types of marine algae - two forms (A, B) of green filamentous and one (C) of green "leaves" from which green and red fibers tufts emerge. Sorry, no ID of any...
Alga A was mounted with glycerol and fructose syrup. Algae B and C - with syrup only. Algae samples were rinsed with distilled water, placed on the slide, excess water was removed with a piece of filter paper, covered with a slip, out-of-the-rims mountant was carefully removed with a wet Q-tip and finally, the sample was sealed with nail polish. Slides were stored in a box on a shelf at home, mostly at a temperature of 25-30C, and humidity 50-75%, without special precautions. The alga A slides are now 2.5 years old, the B and C slides are about two months old.
Brightfield images were obtained with a Plan 16X0.32 objective. All of them were taken with the same illumination and camera sensor ISO. All were referenced to the same white balance. In all images, the contrast and brightness were intensified by 50 and 70% respectively. They were also uniformly resized and cropped. No specific manipulation of colors was done. Each photo is a stack of 4-5 single images.
Unfortunately, background brightness is not uniform across the FOV, because of incompletely aligned somewhat illumination. Yet, the main point is how the mountant preformed. It would have been better to photograph the fresh algae in water, prior to mounting, as a reference of the colors, cell structure, cell size etc, for the future, but I failed to do so in time...; I also note that the syrup has an osmotic pressure, that in principle might affect plant cells some; nevertheless, the present images, at least, suggest the potential of fructose syrup to preserve alga pigments.
As always, comments are welcome.