Chocolate agar

Chocolate agar
Chocolate agar showing Francisella tularensis colonies
Comparison of two culture media types used to grow Neisseria gonorrhoeae bacteria.

Known as overgrowth, note that the non-selective chocolate agar medium on the left, due to its composition, allowed for the growth of organismal colonies other than those of Neisseria 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. (To see N. gonorrhoeae colonies, click to enlarge) .

Chocolate agar (CHOC) - is a non-selective, enriched growth medium. It is a variant of the blood agar plate. It contains red blood cells, which have been lysed by heating very slowly to 56 °C. Chocolate agar is used for growing fastidious (fussy) respiratory bacteria, such as Haemophilus influenzae. These bacteria need growth factors, like NAD and hemin, which are inside red blood cells; thus, a prerequisite to growth is lysis of the red blood cells. The agar is named for the color and contains no actual chocolate.

Chocolate agar alone is non-selective, however with the addition of Bacitracin the media becomes selective, most critically, for the genus Haemophilus. A further variant containing an assortment of antibiotics selects for Neisseria.

Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • chocolate agar — an agar medium containing casein digest, peptone, cornstarch, sodium chloride, and phosphate buffer; sterile hemoglobin or fresh blood is added and the medium heated until the color is chocolate brown. Other agar media may also be used as the… …   Medical dictionary

  • Agar chocolate — con colonias visibles de Francisella Comp …   Wikipedia Español

  • Agar nutritivo — El Agar nutritivo es un medio de cultivo usado normalmente como rutina para todo tipo de bacteria. Es muy util porque permanece solido incluso a relativas altas temperaturas. Además, el crecimiento bacteriano en este agar lo hace en la superficie …   Wikipedia Español

  • Agar CLED — despues de su preparacion …   Wikipedia Español

  • Agar plate — Infobox Laboratory equipment name = Agar plate caption = An agar plate streaked with microorganisms isolated from a deep water sponge. Individual colonies may be seen center right. acronym = other names = uses = Culturing inventor = manufacturer …   Wikipedia

  • Agar Sabouraud — Vista desde abajo de una placa Petri de agar de Sabouraud con una colonia de Trichophyton rubrum var. rodhaini …   Wikipedia Español

  • Agar Manitol salado — o siglas en inglés MSA (Mannitol salt agar) es un medio de cultivo que se utiliza normalmente en microbiología. Permite el crecimiento de un determinado grupo de bacterias mientras que inhibe el crecimiento de otras. Este medio es importante en… …   Wikipedia Español

  • Agar sangre — Eritrocitos en una placa de agar que se usa para el diagnostico de una infección. En de la izquierda es positivo para infeccion por Staphylococcus y en la derecha postivo para un cultivo de Streptococcus El agar sangre es una combinación de un… …   Wikipedia Español

  • agar — A complex polysaccharide (a sulfated galactan) derived from seaweed (various red algae); used as a solidifying agent in culture media; it has the valuable property of melting at 100°C, but not solidifying until 49°C. [Bengalese] bile salt a. an a …   Medical dictionary

  • Thayer-Martin agar — chocolate agar enriched with vitamins and other supplements, to which is added antibiotic inhibitors (vancomycin, colistin, and nystatin), used for the transport and primary culture of Neisseria gonorrhoeae and N. meningitidis. Called also TM a …   Medical dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”