Casella CEL Airborne bacteria sampler - Manual (Page 12)

On completion of sampling, the turntable should be lowered by rotating
control A fully anti clockwise and the petri dish of agar removed from the
turntable by unclipping and removing the sampling head.
The petri dish should be covered and incubated at a suitable temperature
(normally 22 o C or 37 o C) for an appropriate period (24 or 48 hours), so that
individual bacteria captured on the agar can multiply to form colonies, which
can be enumerated using standard plate counting techniques.
The concentration of airborne bacteria present during sampling can then be
calculated by.
By the choice of suitable agar and standard microbial techniques, the bacteria
present on the plate may be further investigated to determine the species
present.
Airborne bacteria concentration =
(
) colony forming units per m 3
Number of colonies present on the plate
Sample volume (m ) 3
Operation
Page 12 of 16
BACTERIA SAMPLER
User Manual