Aseptic Technique Flashcards
What should be done before handling the cultures, moving them, or isolating them?
Flame the inoculating loop.
How many times should you overlap from Q3 to Q4?
Once
What should be done between spreading each quadrant of a streak plate?
Flame the inoculating loop.
How do you heat fix a slide?
- Drop a minute amount of distilled water or saline on the slide.
- Flame loop.
- Hold culture plate lid at an angle and obtain a tiny amount of sample.
- Mix water and sample on the slide.
- Allow to air dry.
- Pass slide through flame three times with smear side up.
What chemical is used first in Gram staining and for how long?
Crystal violet, let sit for 60 seconds.
What chemical is used second in Gram staining and for how long?
Iodine, let sit for one minute
What chemical is used third in Gram staining and for how long?
Gram’s alcohol, rinse for 5-10 seconds or until it runs clear.
What chemical is used fourth in Gram staining and for how long?
Safranin, 1 - 2 minutes
What is the last step of Gram staining?
Blot the slide with kim wipes.
What lens is used to observe Gram stains?
Oil immersion
What color is a Gram positive cell?
Purple
What color is a Gram negative cell
Pink
What characteristics are unique to Gram positive cells?
Thick PGL layer
What characteristics are unique to Gram negative cells?
Thinner PGL layer, outer membrane, periplasmic space
What antibiotics work best on Gram positive bacteria?
Penicillins
What antibiotics work on both on Gram positive and negative bacteria?
Ampicillins
Define the term colony.
A group of bacteria grown from a single cell.
What is done between every step of the Gram stain process?
Rinse with water at a 45 degree angle for two seconds.
What are antibiotics?
- Drugs that destroy bacteria.
2. Drugs that prevent bacterial infection.
Two types of antibiotics
- Bacteriostatic
2. Bactericidal
What do bacteriostatic antibiotics do?
Prevents cell division or processes
What do bactericidal antibiotics do?
Kill or destroy bacteria directly.
When was penicillin discovered?
1928
Who discovered penicillin?
Andrew Fleming
How do dyes stain the bacteria?
The negatively charged bacterial cytoplasm attracts the positively charged dye.
How do the crystal violet and Gram’s iodine interact?
They produce a crystal violet-iodine complex that appear blue.
How do Gram negative cells appear pink?
The bacteria is washed with an alcohol decolorized and then dyed pink with Safranin.
