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Gram Stain Differential stain (Hans Christian Gram, a Danish doctor ). He developed a new method to stain bacteria so they can be visible in specimen samples. Differentiate bacteria into two large groups (the Gram Positive and the Gram negative). Gram status is important in medicine; the presence or absence of a cell wall will change the bacterium's susceptibility to some antibiotics.
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Gram Stain Differential stain (Hans Christian Gram, a Danish
doctor ).He developed a new method to stain bacteria so they can
bevisible in specimen samples. Differentiate bacteria into two
large groups (the GramPositive and the Gram negative). Gram status
is important in medicine; the presence orabsence of a cell wall
will change the bacterium'ssusceptibility to some antibiotics.
Almost all bacteria are described by their Gram stain
characteristics.
Based on differences of Cell wall structures Classifies bacteria
into 2 large groups: Gram-positive and Gram-negative. Gram-positive
bacteria have a thick mesh-like cell wall made of 50% to 90%
peptidoglycan, while Gram-negative bacteria only have around 10% of
their cell wall made up of peptidoglycan. Gram Positive &
Negative Bacteria Reagents for Gram Stain
Crystal Violet (purple). Primary stain; positive stain Stains cell
wall purple Iodine Mordant Combines with primary stainto form an
insoluble complexthat gets trapped inbacterialcell wall Staining
the slide: Start with a heat-fixed slide of your material. Recall,
Gram positive bacteria have a single cell membrane and hardy outer
cell wall made of peptidoglycan. In contrast. Gram negative cells
have two membranes. In between the two membranes is the
*periplasmic space* which contains a layer of peptidoglycan.