QM Solutions has released a range of Mattson Garvin slit-to-agar air samplers.
There are two different versions: an environmental air sampler, which samples the atmosphere, and a compressed gas variant that samples compressed gas lines.
The environmental sampler draws air through a 0.152mm slit at 1ft3 per minute and impinges the particles it contains upon an agar surface 2 to 3mm below the slit.
The agar is contained in a 150 x 15mm disposable culture plate that is rotated by a synchronous drive motor.
The rate of rotation can be varied by the interchangeable drive motors.
After sampling, the plate is incubated and the colonies counted.
This count reflects the number of airborne particles carrying viable organisms.
No dilution or plating steps are required.
Results are expressed as viable particles per unit of air, and a time-concentration relationship may be determined.
In the compressed gas sampler, the pressure of the compressed gas (maximum 125psi, minimum 5psi) is reduced by a constant pressure reducing regulator passed through a 0.152mm slit, and the particles it contains impinged upon an agar surface 2-3mm below the slit.
The agar is contained in the same culture plate as described for the Model 220 above.
At the end of the sampling period, the drive motor and gas supply shut off automatically.
The plate is then removed, incubated and the colonies counted by standard techniques.
The results may be expressed as viable particles or colony forming units per ft3 of gas at atmospheric pressure.
