Detection of airborne pathogens in an airstream is almost impossible, except that certain new technologies offer some promise. If one is not concerned with discriminating pathogens from each other, or from other bioaerosols, then the current technologies for sampling and detection in airstreams may be adapted to this purpose.
Most methods require isokinetic sampling.
This is usually accomplished using sharp edged probes and suction pumps. Some examples are shown in the figure. The collection of samples by filtration is the simplest method and requires microscopic analysis which can be tedious. Different filter porosities are used in stages to collect different sized particles. In an elutriator laminar airflow is introduced into a settling chamber where the particles separate under the influence of gravity according to Stokes Law.