staining procedures

Question 1

simple staining

Answer 1

Involves the use of a single stain to visualize morphological characteristics such as shape and arrangement.

Question 2

stain

Answer 2

a dye that is a salt

Question 3

basic stain

Answer 3

When the chromophore is attached to the positive end, and attracted to the negative end of bacteria

Question 4

acidic stain

Answer 4

when the chromophore is attached to the negative end.

Question 5

T/F basic stain requires heat fixation of the bacteria on the slide

Answer 5

T

Question 6

what consistency should your bacteria and water have on your slide?

Answer 6

skim milk consistency

Question 7

in gram positive bacteria, where does the external negative charge come from?

Answer 7

lipoteichoic acid

Question 8

in gram negative bacteria, where does the external negative charge come from?

Answer 8

lipopolysaccharide (LPS)

Question 9

during a basic stain, how long should you leave your dark stain on for?

Answer 9

1 minute

Question 10

during a basics stain, how long should you leave your light stain on for?

Answer 10

2 minutes

Question 11

acidic stain

Answer 11

when the chromophore attached to a negative end.

Question 12

what will the bacteria look like during a basic stain?

Answer 12

colored bacteria on a light background

Question 13

what will the bacteria look like during an acidic stain?

Answer 13

light bacteria on a dark background

Question 14

is there heat fixation during an acidic stain?

Answer 14

no

Question 15

which stain is better to see shape of the bacteria? why?

Answer 15

acidic stain, there is no heat fixation and easier to see on a dark background

Question 16

what does the 95% ETHOL do to the gram negative bacteria?

Answer 16

weakens the outer membrane, dye seeps through holes (clear)

Question 17

what does the 95% ETHOL do to the gram positive bacteria?

Answer 17

slightly dehydrates the cell and locks in the stain (still purple)

Question 18

examples of basic stains?

Answer 18

methylene blue, crystal violet

Question 19

examples of acidic stains?

Answer 19

nigrosine, india ink

Question 20

in a differential stain, what stain do you add after you wash your plate with 95% ETOH? how long?

Answer 20

safranin stain, 2 minutes

Question 21

at the end of a differential stain, what colors are your gram negative and gram positive bacteria?

Answer 21

gram neg: pink (light)
gram pos: stays purple (dark)

Question 22

what are acid fast stains used for?

Answer 22

mycobacteria

Question 23

do you heat fixate for acid fast stain?

Answer 23

yes

Question 24

what is the primary stain for acid fast stain?

Answer 24

carbolfuchsin (dark red stain)

Question 25

what is carbolfuchsin made of? what does it do?

Answer 25

5% phenol, helps penetrate the hydrophobic membrane

Question 26

in an acid fast stain, is the 5% phenol enough to penetrate the membrane?

Answer 26

no

Question 27

what methods are used in acid fast stains to help penetrate the membrane?

Answer 27

ziehl-neelson method and kinyoun method

Question 28

what is the ziehl neelson method?

Answer 28

use steam as heat.

Question 29

during the ziel neelson method why do you need to use a vent hood?

Answer 29

Because phenolic fumes are being created.

Question 30

what is the kinyoun method?

Answer 30

use carbolfuchsin and add a wetting agent. keep adding wetting agent (tergital) on for 5 minutes

Question 31

for the acid fast stain, what is used as the decolorizer?

Answer 31

95% ETOH

Question 32

what color does the acid fast stain as?

Answer 32

red

Question 33

what color does the non-acid fast stain as?

Answer 33

no color

Question 34

do you need a counter stain in acid fast stain? if so, what?

Answer 34

yes, methylene blue

Question 35

what is the primary stain for the schaeffer (endospore) staining?

Answer 35

malachite green

Question 36

do you need a counter stain for the schaeffer (endospore) staining?

Answer 36

yes, use safranin