This International Standard specifies a standardized method for the quantification of active and/or
total lactic acid bacteria and probiotic strains in starter cultures used in dairy products by means of
flow cytometry. The method is also applicable to probiotics used in dairy products and to fermented
milk products such as yogurts containing primarily lactic acid bacteria.
This International Standard does not apply to taxonomical differentiation of bacteria. Due to its nonspecificity,
the method may quantify other bacteria than those within the scope of this International
Standard, when present in the sample. This may lead to overestimation of the counts.
The minimum bacterial cell concentration in the sample before applying this standardized method
depends on the dilution rates used in the individual protocols. Typically 106 cells per gram or ml are
considered within the minimum range.