Chapter 2.5, Problem 1TQ

Summary Introduction

To review:

The experiment that can distinguish between the motions of bacterial flagella and eukaryotic flagella and to prove that the flagella rotate.

Introduction:

The advancement in the technologies of microscopy leads to the development of more advanced microscopes. They are able to detect/resolve cellular structures that cannot be detected by earlier versions of microscopes. The limit of resolution, as well as detection, of such microscopes, are much more as compared to the earlier ones.

The detection of bacterial flagella depends upon the correct positioning of the specimen. In case the flagella get hidden under the coverslip, then they may not be visible under the light microscope. This can be resolved by using a dark field optics microscope. In these microscopes, the light entering from the source is controlled with the help of “spider� shaped rings. This enhances the contrast between the specimen and the surroundings.

In order to deduce the type of motion produced by the flagella, the specimen must be tied to the slide. Bacteria can be tied to the slide by covering the slide with an anti-flagellin antibody. After this, the motion of flagella must be observed under the microscope by using video microscopy. In case the flagella show rotatory motion, then the cell body will also begin to rotate and if the flagella show motion in a whiplike fashion, then the tied cell will move back and forth.