TIME ’60 / ’70 – ’70 / ’75

THE PREHISTORY

Bourdillon developed a slit sampling technique with a moving plate. This principle was the basis of the Casella slit to agar air sampler during the 1960 decade. 

The Casella included an electric pump that produced an aspiration of air through slit onto a 140 mm Petri dish containing nutrient agar. It was used in hospital for the monitoring of the operating theatres; it was a heavy and large unit with difficulty for the cleaning. 

Other slit-to-agar instruments appeared on the market: the Mattson-Gavin from USA and BAPD from Ligugnana – Pool Bioanalysis Italiana. They were more easy to clean, lighther and of easy manipulation. 

The design philosophy of these samplers is based upon drawing air through a 0.152mm slit at 1 cubic foot/minute and impinging the particles contained therein upon an agar surface 2–3mm below the slit. The agar is contained in a commercially available 140mm X 15mm disposable culture plate which is rotated by a synchronous drive motor. 

Page navigation