Chocolate agar showing Francisella tularensis coloniesComparison of two culture media types used to grow Neisseria gonorrhoeae bacteria.
Known as overgrowth, the nonselective chocolate agar medium on the left, due to its composition, allowed for the growth of organismal colonies other than those of N. gonorrhoeae, while the selective Thayer–Martin medium on the right, containing antimicrobials that inhibit the growth of organisms other than N. gonorrhoeae, shows no overgrowth, but is positive for N. gonorrhoeae bacteria. (Enlarge image to see N. gonorrhoeae colonies)
Chocolate agar (CHOC) or chocolate blood agar (CBA), is a nonselective, enriched growth medium used for isolation of pathogenic bacteria.[1][2][3] 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.[4] In addition, some of these bacteria, most notably H. influenzae, need growth factors such as nicotinamide adenine dinucleotide (factor V or NAD) and hemin (factor X), which are inside red blood cells; thus, a prerequisite to growth for these bacteria is the presence of red blood cell lysates. The heat also inactivates enzymes which could otherwise degrade NAD. The agar is named for its color and contains no chocolate products.
^Segen. "Chocolate agar: Definition". The Free Dictionary. Retrieved 28 September 2012.
^"Chocolate Agar (CHOC)". Anaerobe free systems. Retrieved 28 September 2012.
^Anderson, Cindy (2013). Great Adventures in the Microbiology Laboratory (7th ed.). Pearson. p. 175. ISBN 978-1-269-39068-2.
^Gunn, B.A (1984). "Chocolate agar: A differential medium for gram positive cocci". Journal of Clinical Microbiology. 20 (4): 822–823. doi:10.1128/jcm.20.4.822-823.1984. PMC 271442. PMID 6490866.
Chocolateagar (CHOC) or chocolate blood agar (CBA), is a nonselective, enriched growth medium used for isolation of pathogenic bacteria. It is a variant...
influenzae. Chocolateagar is named for its color, and no chocolate is actually contained in the plate. Thayer–Martin agar is a chocolateagar designed to...
gray colonies on chocolateagar; it also grows on HBT agar. A selective medium for G. vaginalis is colistin-oxolinic acid blood agar. G. vaginalis is...
Culturing it requires carbon dioxide supplementation and enriched agar (chocolateagar) with various antibiotics (Thayer–Martin). It exhibits antigenic...
has been shown to grow well on both blood and chocolateagars.[self-published source?] Chocolateagar is an excellent Haemophilus growth medium, as it...
other agar plate types. For example, blood agar plates (BAP) are made by enriching TSA plates with defibrinated sheep blood, and chocolateagar is made...
the specimen. Blood agar is an enriched medium in which nutritionally rich whole blood supplements the basic nutrients. Chocolateagar is enriched with heat-treated...
Agar (/ˈeɪɡɑːr/ or /ˈɑːɡər/), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red...
Bacterial culture of H. influenzae is performed on agar plates. The strongest growth is seen on chocolateagar at 37 °C in a CO2-enriched incubator. The ideal...
Commons of Canada Children's Hospital of Orange County, California, USA Chocolateagar CHOC-FM, a radio station in Saint-Raymond, Quebec, Canada CHOC-FM (Saint-Rémi...
Aggregatibacter segnis is a species of bacteria. A. segnis can be cultured on chocolateagar. Norskov-Lauritsen N, Kilian M. (2006). "Reclassification of Actinobacillus...
behave in a manner that mimics yaws. H. ducreyi can be cultured on chocolateagar and incubated in an environment with elevated humidity and CO2 enrichment...
featuring chocolateChocolateagar – Growth medium – named for its colour, does not contain cocoa Chocolate fountain – Device for serving chocolate fondue...
tularensis requires special media such as buffered charcoal yeast extract agar. It cannot be isolated in the routine culture media because of the need for...
confirmed when the organism has grown, most often on a chocolateagar plate, but also on Thayer–Martin agar. To differentiate any bacterial growth from other...
creates a depression (or "pit") in the agar on which it is growing. Only half produce the pitting of the agar considered characteristic.[citation needed]...
kidney-shaped, Gram-negative diplococcus. It can be cultured on blood and chocolateagar plates after an aerobic incubation at 37 °C for 24 hours. Cultures revealed...
multocida will grow at 37 °C (99 °F) on blood or chocolateagar, HS agar, but will not grow on MacConkey agar. Colony growth is accompanied by a characteristic...
some strains are positive. E. meningoseptica grows well on blood agar and chocolateagar. Colonies are very pale yellow and may not be easily evident at...
types, including chocolateagar and Thayer–Martin medium with appropriate additives as noted above. Attempted isolation on MacConkey agar is not reliable...
bacterium cultures well on blood agar plates (heart infusion agar with 5% sheep or rabbit blood) and chocolateagar plates. Colonies may not be visible...
factors. Histophilus grows best on chocolateagar at 37 °C with 5-10% CO2 and is unable to grow on MacConkey agar. Cultures have been developed in hopes...
"MacConkey Agar (CCCCD Microbiology". Collin College. Archived from the original on April 26, 2015. Retrieved May 3, 2015. Gunn BA (1984). "Chocolateagar, a...
factory. This candy also uses agar-agar instead of gelatin as a thickening agent and comes in three flavors: chocolate, vanilla, and lemon. In 2021, a...
non-motile microaerophiles that are able to be isolated in pure culture on chocolateagar. . The genus Taylorella was first identified by C.E.D Taylor in 1978...
successfully cultured on chocolateagar and sheep blood agar. No hemolysis has been observed. Growth has been documented on trypticase soy agar, but the size of...
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