LAB: Bacterial Smear Preparation

Question 1

these are used to apply color to bacteria for it to be seen and observed under microscope

Answer 1

staining reagents

Question 2

it is done to make sure that the bacteria will remain attached to the glass slide

Answer 2

heat fix

Question 3

basic stain is applied in what type of staining

Answer 3

Simple staining

Question 4

how does staining takes place in a bacteria

Answer 4

considering the fact that stain are positively charged, the negatively charged surface and cytoplasm of a bacteria will attract to it, thus staining happens

key terms:
- positively charged stains
- negatively charged surface of bacteria
- cytoplasm of bacteria

Question 5

a type of staining technique where only one stain is used

Answer 5

simple stain technique

Question 6

a type of culture where only one species bacterium is present

Answer 6

pure culture

Question 7

define pure culture

Answer 7

a laboratory culture that contains only a single species of organisms

Question 8

what is the difference of pure culture and a colony

Answer 8

a pure culture means that there’s only one strain of organism present; a colony on the other hand, group of organisms living in close associations, and is a product of exponential bacterial cell division

Question 9

TRUE OR FALSE: a colony is considered as a pure culture

Answer 9

TRUE; because it is basically just a group of organism belonging in a same species

Question 10

bacteria can be cultivated in a (2 types of media)

Answer 10

liquid growth medium and solid growth medium

Question 11

it is a liquid growth medium

Answer 11

nutrient broth

Question 12

a solid growth medium

Answer 12

nutrient agar

Question 13

it is thin layer of bacteria placed in a slide for staining

Answer 13

bacterial smear

Question 14

TRUE OR FALSE: bacterial smear is a thick layer bacteria placed in a slide

Answer 14

FALSE; in bacterial smear, the bacteria placed in a slide should be of a thin layer

Question 15

TRUE OR FALSE: it is okay to drag the 40x objective lens through the immersion oil

Answer 15

FALSE: allowing the oil to touch the other objective lenses (aside from the OIO) will damage their lens, rendering them useless

Question 16

it is used to wipe off the oil from the OIO lens

Answer 16

lens paper

Question 17

heat fix is passing the slide through the flame by how many times

Answer 17

3-4 times

Question 18

sources of flame in the laboratory

Answer 18

bunsen burner and denatured alcohol

Question 19

the suggested size of bacterial smear

Answer 19

five-centavo coin

Question 20

TRUE OR FALSE: bacterial smear should be heat-fixed first before air-drying

Answer 20

FALSE; after allowing the liquid to evaporate during the air-drying, bacterial smear should then be heat-fixed.

Question 21

the main goal this technique is to maintain the sterile environment and avoid contamination of unwanted microorganism

Answer 21

aseptic technique