Yeast are transferred on velvet squares in a process called replica plating to produce exact copies of each plate. Notice that some of the colonies do not seem to grow on these 5'FOA plates.

C. elegans with muscle tissue stained with ß-galactosidase and X-Gal. Normal worms (wildtype) with normal muscle tissue have a dark blue staining color, while abnormal (mutants) worms do not and appear more clear.