Classic multipurpose model


Originated in 1925 by Robert W. Dawley from a hybrid hooded male and a female Wistar rat. To Charles River in 1950 from Sprague Dawley, Inc. In 1991, 8 colonies were selected to form the IGS Foundation Colony. Rederived into an isolator foundation colony in 1997. IGS refers to animals bred using the Charles River International Genetic Standardization system.

Strain code


Coat color

White (Albino)

Research application

General multipurpose model, safety and efficacy testing, aging, nutrition, diet-induced obesity, oncology

Breeding location

US, Germany, UK, Italy, Canada