REAL Lab final exam microbiology

REAL Lab final exam microbiology
OCCC Questions with Verified
Answers
Crystal violet – ANSWERS
primary dye in gram stain

Gram's iodine – ANSWERS
causes primary dye to form crystals in the cell walls

Ethanol – ANSWERS
dissolves lipids in the outer membrane and removes the dye from peptidoglycan
layer and gram - cells

Safranin – ANSWERS
secondary stain in gram stain; stains the gram - cells

E. coli – ANSWERS
gram negative, rods, individual

Staphylococcus aureus – ANSWERS
gram positive, cocci, clusters, FERMENTS MANITOL

Bacillus megaterium – ANSWERS
gram positive, rod, chains

spore stain technique – ANSWERS
 aseptically prepare air dried, heat fixed slide
 place blotting paper over smear
 steam bath with MALACHITE GREEN stain for 3 min.
 remove blotting paper
 rinse to get rid of vegetative cells' color
 flood smear with SAFRANIN for 1 min.
 wash slide and blot

acid-fast stain technique – ANSWERS
 aseptically prepare air dried, heat fixed slide
 stain slide with CARBOLFUCHSION on blotting paper and steam bath for 5 min.
 wash slide
 decolorize with ACID-ALCOHOL for 15 sec.
 saturate smear with METHYLENE BLUE for 1 min.
 wash and blot dry