Re: how have advancements in microscopes increased our understanding of cells?

Advancements in microscopy have been as important for cell biologists as have advances in telescopes (eg., Hubble space telescope) have been for astronomers. Use of transmission electron microscopes, beginning in the 1950's, allowed scientists to identify tiny cell organelles such as mitochondria and lysosomes. Knowledge of the two membranes within mitochondria allowed scientists to confirm a key mechanism used by mitochondria to generate energy, i.e., by using the flow of electrons across one membrane to another part of the mitochondria to create ATP.

More recent advances have used fluorescence microscopes that can find the locations of fluorescently labeled proteins. This allows scientists to precisely identify where in the cell individual proteins are located. This type of microscopy provides key clues to what all of the 25,000 proteins coded for by the human genome actually do. Another advance was the development of scanning electron microscopes, which show the 3- dimensional appearance of intact cells that are not cut into sections, as in conventional microscopy.

A brief review of these techniques is presented in Elsevier's Integrated Histology, by AG Telser, JK Young, and KM Baldwin (2007).