<P> Chocolate agar (CHOC) or chocolate blood agar (CBA)--is a nonselective, enriched growth medium used for isolation of pathogenic bacteria . It is a variant of the blood agar plate, containing red blood cells that have been lysed by slowly heating to 80 ° C. Chocolate agar is used for growing fastidious respiratory bacteria, such as Haemophilus influenzae and Neisseria meningitidis . In addition, some of these bacteria, most notably H. influenzae, need growth factors such as NAD (factor V) and hemin (factor X), which are inside red blood cells; thus, a prerequisite to growth for these bacteria is lysis of the red blood cells . The heat also inactivates enzymes which could otherwise degrade NAD . The agar is named for the color and contains no actual chocolate . </P> <P> Chocolate agar with the addition of bacitracin becomes selective, it is most critically, for the genus Haemophilus . Another variant of chocolate agar called Thayer - Martin agar contains an assortment of antibiotics which select for Neisseria species . </P>

Which agar will grow most types of neisseria