Question: Is CNA Agar Selective Or Differential?

What is differential agar?

Differential media are bacteriological growth media that contain specific ingredients to allow one to distinguish selected species or categories of bacteria by visual observation.

Blood agar is one type of differential medium, allowing bacteria to be distinguished by the type of hemolysis produced..

Is blood agar selective or differential or both?

Blood agar is a differential medium that distinguishes bacterial species by their ability to break down the red blood cells included in the media. Blood agar is often used to distinguish between the different species of pathogenic Streptococcus bacteria.

Is MacConkey agar selective or differential?

MacConkey agar is an example of a medium that is both differential and selective. The presence of bile salts, as well as crystal violet, within the media prevent gram-positive organisms from growing.

What grows on CNA agar?

Columbia CNA Agar has traditionally been used to identify staphylococci and streptococci. The addition of sheep blood to the medium allows distinct identification of S. pneumoniae through the production of clear alpha-haemolysis.