Card Set Information
What is aseptic technique?
To transfer living microbes from one place to another without contaminating yourself, others, the sterile medium and the surround
What is the importance of aseptic technique?
To isolate one type of bacteria to get pure culture and avoid getting contaminated with pathogenic bacteria
What is a culture?
A medium that contains living microbes
What is a pure culture?
A medium that contains a single species
What is a mixed culture?
A medium that contains one ore more species
What does liquid/broth use for?
To grow fresh cultures, large volumes, in short amount of time
What is the solid/agar medium use for?
Agar slant, stock cultures, longer storage time.
Plated media used for isolating species, quantifying bacterial densities
What is morphologies? and give some example
Morphologies are shapes.
: cocci (coccus-spheres)
What is Pleomorphism?
When one organism shows several shapes, irregular being normally rod-shaped.
: Corynebacterium xerosis
What is the purpose of staining?
to provide contrast of the specimen against the background so we can view the detail of the cell under microscope.(Morphology, size, and arrangement).
What is arrangement?
When bacteria present different types of division pattern.
What are some type of arrangement?
Chain vs. cluster; diplococcus/ Diplobacilli; tetrad(4 cell together, flat) vs. sarcina( 4 -6 cells on each side, 3 dimension)
What are stains?
Colored molecules which are chromogen dissolved in a solvent(water or ethanol)
What is the portion of the chromogen that gives its color?
What is the portion of the chromogen that is charged?
What are basic stain and what do they get attracted to?
Basic stain has positive auxochrome that is attracted to the negatively charge cell surface.
Ex of basic stain
: methylene blue, crystal violet, safranin.
What is a negative stain?
A negatively charge stain that repel the cell membrane, leaving the cell to appear uncolored on a color background
What is the purpose of heat-fixing the cells?
Kills the bacteria and adhere the cells to the surface of the slide, avoid shrinkage of the cells.