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.
Agar is a gelatinous medium that provides nutrients and a stable, controlled environment for bacteria growth. Most bacteria will grow well using nutrient agar, but some more fastidious bacteria prefer tryptic soy agar. To prepare agar plates, just heat agar and pour it into a sterile petri dish. Swab along any surface to test (your mouth, the bathroom counter, etc.) and then lightly smear in a zig-zag pattern on the surface of the agar plates. Signs of bacteria growth should show within 1-2 weeks. Getting started: