Mmg Lab 2

Front 1

What is definition of smear preparation?

Back 1

-a thin layer of cells immobilized onto a slide through a bacterial culture or a patients sample.

Front 2

What is fixation?

Back 2

-the immobilization of a microorganism and its structures by physical heat or chemical agents

Front 3

What is the purpose of fixing a slide?

Back 3

-kills cells quickly by denatureing enzymes (this stops metabolic activity for more accurate staining)
-to adhere cells to slide better to prevent wash-off

Front 4

How do you label a slide?

Back 4

-Sec/Bench
-Initials
-Date
-Specimen

Front 5

Why is it important to make a slide clean and how do you do this?

Back 5

-microorganism suspension will not spread evenly (or remain) on slide
-clean with abrasive cleanser and hot water to remove dirt and oil

Front 6

What writing utensil do you use to write on the frosted part of a slide?

Back 6

-a graphite pencil

Front 7

How do you smear a broth suspension?

Back 7

-gently shake tube and aseptically pick up a loopful or pipetful of culture and place in wax circle
-spread drop over circle and fill with 1-2 more loopfuls
*remember to sterilize loops between slide

Front 8

How do you smear a slant or agar plate?

Back 8

-place small amount of water in wax circle
-aseptically pick up small amount of organism and touch to water
-when dry, smears should be one cell thick

Front 9

Why should cells be one cell thick when preparing smears?

Back 9

-cells won't be viewable
-cellular morphology and spatial arrangement become difficult to determine

Front 10

How do you generally make a slide?

Back 10

1) Make sure slide is clean
2) label slide and make circles
3) heat wax by passing over flame a few times
4) sterilize loop or needle
5) obtain specimen
6) allow smear to air dry
*bunsen burner drying causes distortion!
7) heat fix slide
8) Stain or store to be stained

Front 11

What is the cause, and how would you fix the problem:
cells won't adhere to slide?

Back 11

-dirty slides
-make sure slides are clean

Front 12

What is the cause, and how would you fix the problem:
water beads up on slide?

Back 12

-dirty slide
-make sure slides are clean

Front 13

What is the cause, and how would you fix the problem:
distortion of cellular shape?

Back 13

-heat fix too long, used flame to dry, hot looping cells, cells spread too vigorously
-shorten fixation, allow to air dry, cool loop longer, spread slowly and gently

Front 14

What is the cause, and how would you fix the problem:
can't see individual cells?

Back 14

-cell layer too thick or not spread out enough
-suspend less, spread smear over larger area

Front 15

What is the cause, and how would you fix the problem:
too few cells on slide?

Back 15

-smear too thin, circle too large, cells wiped off while blotting, added water
-use several loopfuls of culture, minimze area a spreading, blot gently, transfer broth directly to slide and don't add water

Front 16

What is the cause, and how would you fix the problem:
wax circle washes off slide?

Back 16

-wax not fixed or is too thick
-heat wax longer and use thinner lines

Front 17

What is the cause, and how would you fix the problem:
colony does not emulsify in water

Back 17

-colonly is too sticky
-place colony along side the drop of water and spread around to break it up. Then mix pieces with the water.