[[Image:giardia.jpg|rightleft|thumb|400px|This picture shows multiple views of a single Giardia lamblia (intestinalis) cyst as imaged at different instrument settings by confocal microscopy.Bar = 10 micrometres.<br />(A) is the cyst imaged by transmission (differential interference contrast), only.<br />(B) is the cyst wall selectively imaged through use of fluorescent-labelled (TRITC) antibody that is cyst wall specific.</br>(C) is the cyst imaged through use of carboxy fluorescein diacetate, a viability stain.<br />(D) is a composite image of (B) and (C).<br />(E) is a composite image of (A), (B), and (C).]]
Under a normal compound light [[microscope]], ''Giardia'' often looks like a "clown face," with two nuclei outlined by adhesive discs above dark [[median bodies]] that form the "mouth." Cysts have four nuclei.
