Air sampler

A low-cost, simple, portable, electrostatic sampling device has been created at the ARS Southeast Poultry Research Laboratory in Athens, Georgia, for high-efficiency sampling of airborne bacteria, viruses, and spores.

The compact, 2-pound device, developed by agricultural engineer Bailey Mitchell and his colleagues, pulls air and dust particles into it for sampling. “The device samples about 212 cubic feet an hour - enough to sample all the air in a small office in about 2 hours,” said Mitchell.

The battery-operated device is housed in a waterproof enclosure, allowing disinfection after use. “It’s completely sealed and self-contained,” said Mitchell, “so it’s easy to clean and disinfect - very important for ensuring accurate sampling.”

The sampler has good potential for detecting microorganisms present in numbers too small to be recovered by traditional methods, such as swab or serum sampling.

The electrostatic sampling device has been tested extensively in clean lab areas, in exhaust air from poultry houses, and in caged layer rooms with birds infected with Salmonella enteritidis. It’s shown up to a 20-fold improvement over standard settling-plate sampling techniques and has performed better than a well-known and widely used medium-volume, laboratory-grade, portable impaction sampler costing about 100 times more than Mitchell’s device.

A 20-minute-old agar plate culture from an air sample collected by an ARS-developed electrostatic sampling device. The air sample was taken in a caged layer room of birds infected with Salmonella enteritidis.

Mitchell says the device can be used in any area where high-efficiency air sampling is needed. Its small size makes it easy to transport and convenient to place in various locations.

“It’s important to know about contamination as soon as possible so it can be dealt with promptly and thoroughly,” he said. Previous devices with good to high-efficiency recovery were typically large and bulky, difficult to disinfect, or expensive - ranging from $1,000 to $25,000. “This unit has about $50 worth of parts, so even if someone pays $200 for it, that is a lot less expensive than the currently available choices.”

Developed at the Southeast Poultry Research Laboratory in Athens, Georgia, this low-cost, portable electrostatic sampling device performs high-efficiency sampling of airborne bacteria, viruses, and spores.

Tests suggest the electrostatic device, if operated for 2 hours or more, can sample as much air as a high-volume air sampler and can be operated for about 16 hours with two standard 9-volt batteries. Its low cost and simple operation would make it practical for use in hospitals, too.

“It would dovetail nicely with rapid tests for microbes including Salmonella, Listeria, E. coli, and viruses,” Mitchell added.