Example 1. The following spreadsheet uses the Excel Char function to return the character associated with different supplied character set numbers. Note that these results are from the Ansi character set (used on the Windows operating system).
Potassium tellurite agar is selective for the growth of Staphylococci and is somewhat selective for the growth of Corynebacteria. Staphylococci and Corynebacteria reduce the potassium tellurite in the agar, which makes the colonies grow black.
Bile Esculin Agar. This is a medium that is both selective and differential. It tests the ability of organisms to hydrolyze esculin in the presence of bile. It is commonly used to identify members of the genus Enterococcus (E faecalis and E. faecium).