Staining and Imaging Techniques, Bacterial Growth Flashcards
Name 3 examples of basic dyes
crystal violet, methylene blue, safranin
Name 2 examples of acidic dyes
eosin, india ink
What is a disadvantage to using a simple stain?
Doesn’t indicate size of an organism because it shrinks during the procedure
What staining process first applies basic dye, then wash it out with iodine and alcohol/acetone, and then add a counterstain?
gram stain, which is a differential stain
A pink stain demonstrates _____ ______ bacteria
gram negative, stained with safranin
What is a special/structural stain?
Identifies structures within or on cells, and different parts of cells are stained different colors. Example: endopores in some gram positive bacteria (bacillus, clostridium)
Name three examples of special stains
negative (capsule) stain, flagellar stain, flourescent stains
What kind of stain is best in finding true size of an organism?
Negative stain (acidic dye used, not fixed with heat so no shrinkage)
What stain type uses carbol fuschin and heat? What specific cell wall structure is involved in this stain? What kind of bodily fluid is used for this stain, and what kind of bacterial infection are you testing for?
- Acid-fast stain.
- Mycolic acid (lipid) in the cell walls need heat to loosen the cell wall so the carbol fuschin can penetrate for staining.
- Sputum smear is used to test for Tuberculosis
Malachite green, heat, and safranin are used for what kind of staining technique?
Endospore stain
What is unique about a parfocal microscope?
Can change magnifications without losing focus of organism
Ability to distinguish 2 objects as separate/distinct is called_____.
What kind of lens helps increase this property?
- Resolution
2. Oil immersion lens
Closest distance two things can be together and still be seen as separate is called____
resolving power
RP=wavelength of light/(2 x numberical aperture)
Refractive index of material between objective lens & specimen
Name two kinds of electron microscopes
- transmission electron microscope
2. scannng electron microscope
Name 5 physical requirements for bacterial growth
Temperature Oxygen pH Osmolarity Pressure
What can maintain life via fermentation or anaerobic respiration or by aerobic respiration?
facultative anaerobe
What does not use aerobic metabolism, and oxygen is not toxic to them (have enzymes)
aerotolerant anaerobes
What organisms require 2-10% of oxygen?
microaerophiles
Which microbes (based on temperature range) cause disease in humans since they are at body temperature?
MESOphiles
Name three classifications of bacteria based on pH growth factors. Which organisms grow best in which classification?
1-neutrophiles (6.5-7.5 pH)- bacteria and protozoa
2-acidophile (grow best in acidic habitats)- other bacteria and fungi
3-alkalinophiles (live in alkaline soils/water up to 11.5 pH)
a solution with lower solute concentrations will lead to the cell swelling and bursting. this is in _________ state
hypotonic
a solution with higher solute concentration will lead to plasmolysis (shriveling of cytoplasm)t. this is in ____________state
hypertonic
________ grow in up to 30% salt. __________ can tolerate high salt concentrations (give an example)
1-obligate halophiles
2-facultative halophiles- example is staph
organisms that live under extreme pressure to maintain their 3-d and functional shape are called ______________
barophiles
Describe the four phases of microbial growth
- Lag phase-Organisms are acclimating
- Log phase-Logarithmic increase in cell number
- Stationary phase-Nutrients depleting, waste accumulating (Growth = dividing cells)
- Death phase- Dying > dividing
