New national conversion line for Bactoscan FC in Italy: A step forward

To improve the reproducibility of flow cytometry technique for total bacterial count in milk, a conversion from instrumental results (impulses/μL) to the reference method resultes (cfu/mL) is needed. In 2008 in Italy, a project for a common conversion line for Bactoscan FC was initiated. In this paper we report on the second phase of the project focusing on the statistical procedure used to evaluate the validity of the data. The new conversion line, representative of national milk (2,732 valid samples from 29 labs) obtained from both rounds of the study is: Log10 (cfu mL-1) = Log10 (IBC μL-1) x 0.939 + 2.559, with S y:x= 0.282 with an application range up to 70,000 IBC μL-1.