| Giardia lamblia is the most common intestinal parasite identified in the U.S. The cysts, shown at right, are oval measuring from 11 to 14 µm in length and 7 to 10 µm in width. Four nuclei are usually visible along with axonemes, and median bodies. Often, the cyst will appear shrunken, pulling away from the cyst wall. |  |
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The trophozoites are described as having a 'tear-drop' shape and are 10 to 20 µm long and 5 to 10 µm wide. The trophozoites contain two nuclei, four pair of flagella, two axonemes, and two curved bodies called the median bodies. The image at left is from an iodine-stained wet-mount (1000x). |
| The image at right is a wet mount of a trophozoite viewed by phase-contrast microscopy. Image courtesy of Gustavo Gini. |  |
Copyright 2008 Don Lehman