The following photos and short video are intended to give you a feel for the Red and White Yeast system.

Briefly, last week, we spread a dilute suspension of yeast cells (the same species that is used in baking bread) in a patch on a petri dish containing solid nutrient medium. A Petri dish is a plastic dish roughly 4 inches in diamter and 1/2 inch tall. The "solid nutrient medium" is food for the yeasts mixed with agar, a substance like gelatin that, makes the medium solid. A side view is shown below:

Between this lab and the next, the yeast will grow. They do this by increasing in number several million times. Over this time, the cells in the patch develop a characteristic color pattern: the center is red and the edge is white. This is shown below, roughly actual size:

The next image is a close up of the patch:

The next image is an extreme close-up of the lower part of the patch:

The following is a time-lapse movie of the growth of the patch. The movie is not of very good quality; the still images are there to help you ignore all the irrelevant parts of the movie.

Here is the movie: