VDI 4253 Blatt 4:2013-02

The guideline describes an evaluation method for quantification of the total cell count of microorganisms by microscopic counting after staining of DNA-containing structures. It is a cultivation-independent method for analysis of ambient air samples, emission samples and indoor air samples in the course of which living and dead microorganisms are detected. The use of this analytical method is particularly advisable if microorganisms are subject to hostile environmental impacts on their way from the emission source to the sampling location. This guideline is aimed at a concentration range starting from 105 GZZ/m3 for sampling with impingers at an air sampling volume of 0,5 m3. For lower expected total cell counts higher air sampling volumes are necessary which can be obtained by means of filtration methods with polycarbonate filters.