transfer of microbes from their pure culture to a sterile medium without contamination of yourself, the environment, the source culture, or the medium being inoculated
safety practices for aseptic transfers
1) minimize the potential of contamination 2) be organized 3) place all media tubes in a test tube rack when not in use whether they are sterile or not 4) take your time 5) never hold a tube culture by it's cap 6) hold the inoculating loop or needle in your hand like a pencil in your dominate hand 7) adjust your bunsen burner so your flame has an inner and outer cone
used to grow microbes when fresh cultures or large numbers of cells are required
generally used to grow stock cultures that can be refrigerated after incubation and maintained for several weeks
typically used for obtaining isolation of species, differential testing, and quantifying bacterial densities
instruments used for transfers
inoculating loops or needles
a microbial culture consisting of two or more species
commonly used isolation technique
term used to define a cell or a group of cells that grows into a colony
the basic categories of colony morphology
shape, margin (edge), elevation, texture, and color
colony shape can be described as :
circular, irregular, or punctiform (tiny)
colony margin may be described as:
entire (smooth with no irregularities), undulated (wavy), lobate (lobed), filamentous, or rhizoid (branched like roots)
colony elevations can be described as:
flat, raised, convex, pulvinate (very convex), and umbonate (raised in the center)
colony texture can be described as:
moist, mucoid, or dry
colony pigment production can be described as:
color, opaque, translucent, shiny, or dull
dense and opaque with a smooth edge
Most species in the genus Mycobacterium produce ___ growth.
2 important factors influencing bacterial growth
incubation time and temperature
What organisms were used in the colony morphology experiment?
Why are growth characteristics more useful on agar plates than on agar slants?
the plates have a larger surface area for streaking to isolate
Why are agar slants better suited than agar plates to maintain stock cultures?
Slants are better suited because they can be capped, preventing the agar and culture from drying out. The cap also prevents airborne contaminates from entering the slant. Slants take up less storage space.
produces colored growth
solid growth seeming to radiate outward
surface membrane caused by organisms floating on top of the medium
organisms that sink to the bottom of the medium
introduction of a small sample of inoculum into a container of media to produce a culture of observable growth