MacConkey's Agar showing lactose positive pink colony above a lactose negative colorless colony.
MacConkey's Agar showing lactose positive pink colony above a lactose negative colorless colony.MacConkey's Agar showing lactose positive pink colony above a lactose negative colorless colony.MacConkey's Agar showing lactose positive pink colony above a lactose negative colorless colony.
MacConkey's Agar showing lactose positive pink colony above a lactose negative colorless colony.
Science Image Library: MacConkey's Agar (MAC)


Science Image Library
MacConkey's Agar Bacterial Growth Medium

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MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.

Example of Colony Morphology of Bacteria Grown onMacConkey's
Examples of various Gram-negative bacterial colony morphologies grown on MacConkey's Agar (MAC)
Bacterial Growth on MacConkey's Agar. Lac - Salmonella Left, Lac + E.coli Right
Bacterial Growth on MacConkey's Agar. Lac - Salmonella Left, Lac + E.coli Right
Bacterial growth on MacConkey's Agar. Lac - Salmonella left, Lac + E.coli right. 
E. coli Bacteria Written and Growing on MacConkey's Agar.
E. coli bacteria written and growing on MacConkey's Agar. 
E. coli Lac + Bacterial Growth on MacConkey's Agar
E. coli lac + bacterial growth on MacConkey's Agar. 
E. coli on MacKonkey's Agar That Has Dried Up
E. coli lac + bacterial growth on MacConkey's Agar. On this plate, the MAC Agar and bacteria have dried out.
MacConkey's Agar showing lactose positive pink colony above a lactose negative colorless colony.
MacConkey's Agar showing lactose positive pink colony above a lactose negative colorless colony.
MacConkey's Agar Growing a Pink Smiley Face of E. coli
MacConkey's Agar growing a pink smiley face of E. coli.
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Prokaryotic Cell, Mariana Ruiz
Lactose Fermenting Gram-negative Bacteria Growing on MacConkey's Agar
Page last updated 4/2014
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SCIENCE PHOTOS
MacConkeys (back) & TSY agar (front) growing environmental sample from kitchen sink.
MacConkeys (back) & TSY agar (front) growing environmental sample from kitchen sink.
Bacterial unknown plated both on Mannitol Salt and MacConkey's
Unknown bacteria plated on Mannitol Salt Agar  (left) and MacConkey's (right). Note that there is no growth on MacConkey's. So what do you think the unknown bacterium is?
Sterile Plate of MacConkey's Agar MAC
Sterile Plates of Specialized Bacterial Growth Media: MacConkey's, Mannitol Salt and Bloog Agar (clockwise from top left)
Sterile plate of MacConkey's Agar photo on left. Sterile plates of MacConkey's, Mannitol Salt and Blood Agar (clockwise from top left) photo on right
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MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.
MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.
MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.
MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.
MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.
MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.
MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.MacConkey's Agar growing Gram-negative bacteria; pink lactose fermenting bacterial colony above colorless non-lactose fermenting bacterial colony.
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VIDEO: MacConkey's Agar Quiz and Review - How to Interpret MA​C
VIDEO: MacConkey's Agar (MAC) 
Bacterial Growth Medium
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Learn more about this  specialized medium in the SPO article:

MacConkey's Agar (MAC)

MacConkey's Agar Growing E. coli, Enterobacter & Salmonella (clockwise from top left plate)
MacConkey's Agar growing E. coliEnterobacter & Salmonella (clockwise from top left plate).
MacConkey's Agar control plate growing E. coli (pink),  & Salmonella (colorless). Staph epi and Staph aureus were also plated on this control, but did not grow because they are Gram+.
MacConkey's Agar growing E. coli. Note pink color of bacteria due to lactose fermentation.
MacConkey's Agar growing E. coli. Note pink color of bacteria due to lactose fermentation.
MacConkey's Agar growing Enterobacter. Note uneven pink color characteristic of a weak lactose fermenter.
MacConkey's Agar growing Enterobacter. Note uneven pink color characteristic of a weak lactose fermenter.
MacConkey's Agar growing  Salmonella. Note colorless growth due to the bacteria NOT being a fermenter. .
MacConkey's Agar growing  Salmonella. Note colorless growth due to the bacteria NOT being a fermenter.