The presentation explains the basic technique involved in enumeration of microbes from air

1. ENUMERATION OF
MICROBES FROM AIR
ASSISTANT PROFESSOR
SRCW

2. INTRODUCTION

3. ENUMERATION OF
MICROORGANISMS IN AIR
Various methods commonly applied for
enumeration and detection of microorganisms can
be subdivided into:
• Microscopic methods
•Culture methods
•Combination of both

4. MICROSCOPIC METHODS
Letting the air through
filter paper
Placed on a glass slide
using Vaseline
Staining of trapped
microorganism
Fluorescent microscopy –
Acridine orange
Live and Dead can be
differentiated

5. DRAWBACK
• Possible to detect and identify other biological agents e.g. plant pollen,
allergenic mites, abiotic organic dust (fragments of skin, feathers,
plants, etc.).
• Inability to determine the species of microbes (bacteria, fungi,
viruses).

6. CULTURE METHODS
CULTURE
METHODS
Impingement in
liquids
Impingement on
solids
6

7. IMPINGEMENT IN LIQUIDS
Observation
of growth
Incubation
Organisms
get trapped
in the
medium
Air drawn through
small
opening/capillary
tubes

8. Preparation of culture medium
Nutrient Agar
PDA
Exposing to Air
Incubation at Bacteria : 37℃ for
24hrs
Fungi : Room temp
Counting Colonies
Microscopic examination
IMPINGEMENT ON SOLIDS