Biocapt
The microbiological air sampling of clean rooms is performed to ensure that the levels of air borne micro organisms are within the recognised International Standard.
The BIOCAPT has been designed to ensure a very high sampling efficiency for any particles with bacterial contamination. The BIOCAPT sampling head has been designed for different air systems such AIRCAPT and MINICAPT. This air sampler pulls air through the BIOCAPT sampling head, a metal plate with rectangular slits, onto an agar plate where particles are deposited on the agar surface.
Any micro organism collected from the air will be deposited through the slit onto the grooves caused by the airflow. This allows any colonies collected from the air to be distinguished from any contamination on the plate, as the contaminating colonies will be not limited to the grooves. A series of tests have been carried out on the BIOCAPT head to determine the performance using a technique described in the ISO 14698.
The effectiveness of the microbiological air sampler can be split into two sides, the physical and the biological. The physical side of the sampler has the ability to collect air borne particles of all sizes, whilst the biological side of the sampler has the ability to collect air borne micro organisms and render them non-viable.
The physical efficiency of the sampler was measured throughout the particle size range of 1-10 microns by creating an aerosol of the aero-stable bacterial spore, Bacillus Subtilis Var Niger. Aero-soling from a range of concentrated Potassium Iodides solution varied the size of the particles containing spores.
The biological efficiency of the sampler was compared to a standard slit sampler using a mixed aerosol of the aero-stable spore and common air contaminant, Staphylococcus Epidermidis.
The ratio of the number of the Staphylococcus Epidermidis cells collected to the aero-stable spores gives an indication of the biological efficiency of the BIOCAPT.
Physical efficiency of the Minicapt PS1 sampler with BIOCAPT sampling head compared to a FILTERT sampler:
% Kl | Measured mean Particle size µ | 25 l/min | 50 l/min |
0 | < 1 | 50.7% | 79.2% |
0.007 | 1.2 | 42.3% | 73.4% |
0.07 | 2.8 | 68.0% | 95.0% |
1.4 | 5.4 | 99.3% | 100.6% |
7.0 | 9.2 | 125.4 | 105.8 |
Biological efficiency:
Sampler type | Sampling time(min) | Numbers of runs % | Biological efficiency |
Biocapt 25 l/min | 1 | 10 | 86.2 |
Biocapt 50 l/min | 1 | 10 | 95.3 |
Biocapt 50 l/min | 10 | 3 | 82.4 |
The BIOCAPT sampler can recover the aerosol of Staphylococcus Epidermidis with a high efficiency.
There is no evidence of significant reductions in the recovery of Staphylococcus Epidermidis during a 20-minute sampling time.
