24 July, 2015

Summer vacation research project?

©Illustoya
By a request of my colleague, I summed up how to prepare samples for optical microscopes so that both of children and adults can enjoy this workshop. For my record, I'm describing here.

In this workshop, the magnification of a light microscope can be 60x at a maximum.So I proposed my colleague to make banana and potato samples. We can easily observe these starch granules using 10- to 60-power magnifications, and these can be purchased at any supermarkets.

Banana
(1) Insert a toothpick in its white pulp, and take a little bit small section.
©Illustoya
(2) Load a drop of distilled water in the centre of a slide glass.
(3) Mix (1) with distilled water on the slide glass.
(4) Cover (3) with a cover slip.
(5) Observe it in a microscope.

Potato
(1) Cut potato, insert a toothpick in its cross-sectional surface, and take a little bit potato water.
(2) Load a drop of distilled water in the centre of a slide glass.
(3) Mix (1) with distilled water on the slide glass.
(4) Cover (3) with a cover slip.
(5) Observe it in a microscope.

We can buy distilled water at pharmacies.

Stained starch grain is more easily observed. Put distilled water to dilute mouthwash containing iodine (brownish-red, iodine tincture or Lugol's solution) by 10 times and use phase (2).

Due to cover sample liquid with water, a cover glass may be removed during the observation. For keeping it from moving, paint four sides of a cover slip by a topcoat of clear polish.

I mount samples by glycerol gelatin (manufactured by Sigma, a refractive index of 1.46-1.48) and a topcoat of clear polish in my research.

If you have a chance, please enjoy this experiment.

No comments:

Post a Comment