Microscopy Primer
Light and Color
Microscope Basics
Special Techniques
Digital Imaging
Confocal Microscopy
Live-Cell Imaging
Microscopy Museum
Virtual Microscopy
Web Resources
License Info
Image Use
Custom Photos
Site Info
Contact Us

The Galleries:

Photo Gallery
Silicon Zoo
Chip Shots
DNA Gallery
Amino Acids
Religion Collection
Cocktail Collection
Screen Savers
Win Wallpaper
Mac Wallpaper
Movie Gallery

Phase Contrast Image Gallery

Amphibian Red Blood Cells

Most mammalian red blood cells are highly evolved and have lost their nucleus. The nucleated red blood cells illustrated in the phase contrast optical micrograph below were derived from a frog, but are common to all amphibians.

Circulatory systems have evolved to form the most efficient oxygen transport mechanism that is possible for the organism. Oxygen is carried by hemoglobin molecules that reside within red blood cells in all advanced species. In order to maximize the distribution of blood throughout the vessels, hearts have increasingly evolved to accommodate more complex creatures. Fish hearts are relatively primitive and have only two chambers, whereas amphibian hearts are somewhat more advanced with three. The most sophisticated four-chamber hearts are found in reptiles, birds, and mammals.

Having three chambers, the amphibian heart is rather unusual in that it has two atria and only a single ventricle. This complicates matters because blood accumulates oxygen in the lungs and is then returned to the heart before being pumped into the rest of the circulatory system. A problem arises because blood returning to the heart from the lungs is mixed with incoming blood from the body, causing a mixing between oxygenated and deoxygenated blood. Amphibians deal with this situation by having a very slow metabolism, and also by absorbing some oxygen through their skin. In addition there is some directionality in controlling the distribution of blood flow by the ventricle.

The presence of a nucleus in the amphibian red blood cells allows researchers easy access to large quantities of amphibian DNA. This is also true for birds. Blood can be collected from these creatures and the red blood cells isolated by centrifugation. After removal of the residual plasma, purified cells can then be treated with specific enzymes and detergents to digest the cellular envelope and release DNA from its protein complex.


Questions or comments? Send us an email.
© 1998-2022 by Michael W. Davidson and The Florida State University. All Rights Reserved. No images, graphics, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.
This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.
Last modification: Friday, Nov 13, 2015 at 02:19 PM
Access Count Since October 18, 1999: 100600
For more information on microscope manufacturers,
use the buttons below to navigate to their websites: