Lab 5 Flashcards
Gram Stain (25 cards)
Gram stain
differential stain with four steps
heat fix
gram-positive
cell membrane
peptidoglycan, thick wall
is a thick net that crosses with teichoic acids
the wall gets smaller and holds color
appears purple
gram-negative
cell membrane and outer membrane
thin peptidoglycan
negatively charged cells
dissolved outer membrane, stain escapes
appears pink
primary stain
puddle in, 1min
crystal violet
positive charged
mordant
puddle in, 1 min
then rinse with H20
gram’s iodine
primary stain to bind more tightly to some cells
forms complexes, wraps around cell
decolorizer
tip and drip, 5 sec
then rinse with H20
acetone alcohol
some cells retain color, others don’t
dehydrates: where color leaves
secondary stain
puddle in, 1 min
rinse with H20
blot dry with bibulous paper
safranin
positive charge, sticks to everyone, pink
different contrasting color
bacterial cells more fragile with age
destain much easier than younger cells
Staphylococcus aureus
BSL-2 found on skin and in nose
medium purple balls/ staphylococci
Klebsiella pneumoniae
BSL-2 can cause pneumoniae in kids
long pink rods/bacillus
Candida albicans
BSL-1 member of our bodys normal microbiota
large purple with small purple ball connected/
Enterococcus faecalis
BSL-2 found in animal feces
small purple connected balls/streptococci
Moraxella catarrhalis
BSL-1 found in skin and nose
small pink connected balls/diplococci
Bacillus cereus
BSL-1 common soil microbe, forms endospores
purple connected rods/ streptobacilli
Rhodospirillum rubrum
BSL-1 phototropic microbe from soil
long pink squiggles/corckscrew’s form
desquamated cheek cells
round capsule and center cell pink
small connected purple balls/diplococci
coccus
small ball
diplococci
two small balls connected
streptococci
chain of small balls connected
staphylococci
triangle of balls
coccobacillus
oval rod
bacilus
rod
diplobacilli
two chain of rods
streptobacilli
chain of rods
