The video is a time lapse of crystallizing Vitamin C.

A piece of papaya was squeezed between the microscope slide and cover glass. The sample was observed in polarized light.

Many microscopic specimens are either very thin or transparent or lack color. They lack contrast and can not be easily seen in bright microscope light. In many cases it is not possible or desirable to chemically stain the specimens. In this case, optical techniques become necessary to enhance contrast.

Both images depict Vitamin C (Ascorbic Acid) crystals under low magnification using crossed polarizing filters.

It is not necessary to purchase a dedicated polarizing microscope to observe specimens in polarized light. A pair of linear polarizing filters is enough.

Crystals of organic substances make interesting microscopic specimens to be viewed under polarized light.