Laboratory 4g
Bacteria Cell Culture
Background
For DNA extraction purposes, it is desirable to use
a broth culture of cells. The broth culture must
be “started” 1 or 2 days in advance, from a plate
culture, to ensure that there is a high density of cells
in the culture.
The broth culture is started from a single colony
grown on agar plates. Using a single colony of
identical cells ensures that all cells in the broth
culture are identical (see Figure 4.9).
Materials
Laminar flow hood
or biosafety cabinet hood
Lysol® disinfectant
LB agar plates/broth (from
Labs 4e and 4f)
E. coli, stock plate
Glasses, safety, plastic
Bunsen burner
Lab gas lighter
Inoculating loop, Ni/Cr wire
or sterile, plastic, disposable
inoculating loops
Incubator oven,
37°C
Tubes, 50 mL,
sterile, conical
Tube racks for
50-mL tubes
Pipets, 10 mL
Pipet pump, green
Water bath, 37°C,
shaking
Figure 4.9. Bacterial cell cultures are started
on agar Petri plates. Using a sterile inoculating
loop on a sterile bench, a sample is streaked
out until some cells are spaced individually
on the agar. H