#bacterium notes

-- invented by Hans Christian Gram in 1884

-- helped distinguish groups of bacteria

-- identifies cells based on their ability to absorb certain dyes

-- gram-positive = cell does not remove the dye

-- gram-negative = cell does not hold dye, and is stained with a counterstain

-- cell walls that absorb the dye are made of peptidoglycans

-- alcohol does not remove this dye

-- lipopolysaccharides do not hold the dye

-- these are bleached with alcohol easily

-- gram-negative examples      -- pseudomonas      -- legionella      -- hemophilus

-- gram-positive examples      -- staphylococcus      -- clostridium      -- listeria