Stool sample from an individual with gastroenteritis.

An astrovirus image from the ICTVdB.

micrograph prepared by Dr Hans Ackermann, Department of Microbiology, Laval University, Quebec, Canada. Specimen stained with 2 % PTA . The bar represents 100 nm. Primary magnification 29,700 x

A colorized electron micrograph from Prof. Stewart McNulty, Veterinary Sciences, Queen's University, Belfast, UK.

Method: Negative-stain Transmission Electron Microscopy. From the EPA's Microbiology Website.

Note the star-like images exhibited by individual virus particles. These are distinct from the 'Star of David' image exhibited by typical calicivirus particles. Bar = 50 nanometers.