Simple Staining Lab

Question 1

what is Simple Staining

Answer 1

the bacterial smear is stained with a single reagent which produces a distinctive contrast between the organism adn its back-ground.

Question 2

bacteria carry a ___ charge

Answer 2

negative -

Question 3

basic stain is what charge

Answer 3

postivie +

Question 4

bacterial ______ ______ and ______ ____components carry a negative charge that strongly attract and bind to cationic chromogen.

Answer 4

nucleic acid and cell wall

Question 5

cationic vs. anionic

Answer 5

cationic is +
anionic is -

Question 6

what is the purpose of simple staining

Answer 6

to see the morphology (shape) and arrangement of bacterial cells

Question 7

most commonly used basic stains (3)

Answer 7

methylene blue, crystal violet, carbol fuchsin

Question 8

Escherichia coli gram status

Answer 8

gram -

Question 9

Escherichia coli shape

Answer 9

bacillus

Question 10

color Escherichia coli

Answer 10

colorless but when grown on MacConkey agar, E. coli can produce colonies that appear pink due to lactose fermentation.

Question 11

Bacillus cereus gram status

Answer 11

Gram-positive

Question 12

Bacillus cereus shape?

Answer 12

bacillus, chains

Question 13

Bacillus cereus

Answer 13

colorless: when grown on specific media, such as blood agar, it may produce a slight discoloration due to hemolysis

Question 15

three types of bacillus

Answer 15

vibro, spirilla and spirochetes

Question 16

spirilla vs spirochetes

Answer 16

spirilla = helical and rigid
spirochetes = helical and flexible

Question 17

some simple stains are not heat fixed

Answer 17

FALSE - all simple stains are heat fixed

Question 18

procedure for simple staining

Answer 18

place slide in staining tray

flood smear with dye

wait 1-2 minutes

wash smear with tap water , hold slide at an angle so you dont lose organisms

blot dry with bibulous paper do not wipe

Question 19

if you forget to heat fix what will happen

Answer 19

bacteria will wash away when you stain

Question 20

during a coffee break your friend spills coffee on you lab coat and the fabric is discolored is this a true biological stian or simle a cmpound capable of imparting color

Answer 20

rue biological stains are specific dyes used in microbiology and histology to highlight particular cellular structures or components, often with a specific chemical interaction. Coffee, on the other hand, contains natural pigments and compounds (like tannins) that can stain fabrics but do not have the same specificity or purpose as biological stains.