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17 Cards in this Set

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What is definition of smear preparation?
-a thin layer of cells immobilized onto a slide through a bacterial culture or a patients sample.
What is fixation?
-the immobilization of a microorganism and its structures by physical heat or chemical agents
What is the purpose of fixing a slide?
-kills cells quickly by denatureing enzymes (this stops metabolic activity for more accurate staining)
-to adhere cells to slide better to prevent wash-off
How do you label a slide?
-Sec/Bench
-Initials
-Date
-Specimen
Why is it important to make a slide clean and how do you do this?
-microorganism suspension will not spread evenly (or remain) on slide
-clean with abrasive cleanser and hot water to remove dirt and oil
What writing utensil do you use to write on the frosted part of a slide?
-a graphite pencil
How do you smear a broth suspension?
-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
How do you smear a slant or agar plate?
-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
Why should cells be one cell thick when preparing smears?
-cells won't be viewable
-cellular morphology and spatial arrangement become difficult to determine
How do you generally make a slide?
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
What is the cause, and how would you fix the problem:
cells won't adhere to slide?
-dirty slides
-make sure slides are clean
What is the cause, and how would you fix the problem:
water beads up on slide?
-dirty slide
-make sure slides are clean
What is the cause, and how would you fix the problem:
distortion of cellular shape?
-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
What is the cause, and how would you fix the problem:
can't see individual cells?
-cell layer too thick or not spread out enough
-suspend less, spread smear over larger area
What is the cause, and how would you fix the problem:
too few cells on slide?
-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
What is the cause, and how would you fix the problem:
wax circle washes off slide?
-wax not fixed or is too thick
-heat wax longer and use thinner lines
What is the cause, and how would you fix the problem:
colony does not emulsify in water
-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.