Cleared & Stained

A chemical process known as clearing and staining reveals the skeletal anatomy (bones and cartilage) of an animal. The process helps scientists compare different species, determine evolutionary relationships, and study developmental stages.

A digestive enzyme called Trypsin is used to remove all tissue except for transparent connective tissue. Two dyes are added. Alcian blue colors cartilage and Alizarin red dyes bone. Cleared and stained specimens are fragile and stored suspended in glycerin.

KU researchers in our Ichthyology division have developed further methods to help scientists understand the anatomy and movements of fish as well as other animals. Learn more about their work, which was featured in National Geographic magazine, Skeleton photos are getting a boost with the help of gelatin.