Lab Practicum 1 Flashcards
What type of stain is a background stain that is also an indirect stain?
Negative Stain
What acidic dye did we use for the negative stain?
Nigrosin
What stain uses basic dyes that are positively charged?
Simple Stain
In a simple stain, what is the drying time for Methylene Blue? Crystal Violet? Safranin?
Methylene Blue: 2 minutes
Crystal Violet: 30 seconds
Safranin: 2 minutes
What are the steps of the bacterial smear?
- 1 drop of bacteria in middle of the slide
- 1 drop of deionized water closer to the side of the
slide - Mix
- Air Dry for time depending on the dyes
- Heat fix
What is the procedure for a simple stain?
- Bacterial Smear
- Flood the slide with basic dye of your
choice - RInse off
- Blot dry
What type of stain is a Gram stain?
a differential stain
What are the two bacteria we used with the Gram Stain?
- Escherichia Coli
2. Staphylococcus
What are the steps for the Gram Stain?
- Using Crystal violet (primary stain)- dry for
30 sec - Rinse off
- Use Gram’s Iodine (mordant)- dry for 1
minute - Rinse off
- Use 95% ethanol (decolorizing) - Dry for 30
sec - Rinse off
- Flood with Safranin (counterstain) - dry for 2
minutes - Rinse off
- Blot dry
What type of stain is an Acid Fast Stain?
a differential stain
What is a mycobacterium?
a mycolic acid (lipid)
What are the two bacteria we used in the Acid Fast Stain?
- Escherichia Coli
2. Mycobacterium Smegmatis
What are the steps of the Acid Fast Stain?
- bacterial smear
- 80-85 degrees on hot plate
- Put filter paper on top of slide glass
- Add Carbolfuchsin to the filter paper
- Keep wetting it for 5 Minutes
- Peel off filter paper
- Put inside staining tub and wait for it to cool
- Rinse off remaining Carbolfuchsin with water
- Flood with Acid Alcohol for 30 seconds
- Rinse off with water then flood with methanyl Blue for 2
minutes - Rinse off Methanyl Blue and blot dry
What bacteria is used in a Spore stain?
Bacillus Subtilis
What is a Spore stain?
an endospore stain that differentiates the spores
What are the steps of the Spore stain?
- Put on slide glass and Bacterial Smear
- 80-85 degrees; filter paper and Malachite green for 5
minutes - Peel off filter paper and put inside staining pan
- flood with safranin for 2 minutes
- Rinse and then blot dry
What are the steps for a capsule stain?
- Negative stain with nigrosin
- Put in staining tub; Flood slide glass with crystal violet for 30 seconds
- Rinse off with .85% NaCl (=saline sol)
What are the 5 Sterilization Methods?
- Autoclave (121°C for 15-20 minutes, 15 psi)
- Dry Heat (160-170°C for 2 hours)
- UV Radiation (260nm)
- Filtration (.22 um)
- Ethylene Oxide (Gas)
What are the physical states of culture media?
- Liquid(broth)- to obtain large amount of cells per unit
medium - Semi-Solid: in test tube, like jello substance
- Solid: i) to obtain pure culture ii) to observe the colony
appearance iii) storage
What are the ingredient types of media?
- =components
- Complex = Yeast extract, Beef extract, peptones…
- Chemically Defined = mainly for autotrophs; various
chemicals are examples
https://www.microscopemaster.com/parts-of-a-compound-microscope.html
link for microscope parts and their functions
