The Size of Things:

Typical Spatial Scales at the Cellular Level

To characterize the spatials scales involved in biological processes, we first need to know at what scale we see things through the microscope. In each picture the smallest markings are 10um apart; images are 10X, 40X and 100X. Notice all subsequent images have scale bars; made possible by these calibrations.

Yeast & E. coli

Dark-field microscopy of a sample containing the prokaryotic and eukaryotic rulers: E. coli and Yeast.

RBC's & 3T3's

Mammalian red blood cells subjected to an osmolar gradient, notice the change in cell morphology. Imaged in phase contrast.	3T3 cells fixed to a glass coverslip, imaged in brightfield.
Fluorescent and brightfield images of the same transformed E. coli expressing GFP.

The Infamous Sea Urchins

Rob explains how to extract the gametes from living sea urchins.	Rob has stirred Bob Meyer's interest.
Unfertilized sea urchin egg as extracted from full grown living urchins, imaged in phase contrast.	Eggs and sperm extracted from living urchins are mixed in solution to facilitate fertilization - see the fertilization and first division movies in The Rate of Things.

The Amazing Stentor

Stentor the largest single celled organism decided to take a swim. Imaged in brightfield.	A closer look reveals cilia on the back end of the stentor. Imaged in phase contrast.
A stentor stops to feed, cilia at the opening in the front produce fluid flows which move large volumes of water through the mouth area.	A more focused image allows us to determine the line density of cilia on the mouth of the stentor.