The TriMSA software

TriMSA is an easy and efficient software for validation of microbiological methods. It offers two modules for

  • Qualitative methods
  • Quantitative methods

Modules for Qualitative Methods

Most probable number (MPN)

This module provides an estimation of MPN with its 95% confidence interval, and allows the comparison of MPN’s detected by two microbiological methods.

Most probable limit (MPL)

This module is an extension of the MPN approach. It estimates the limit of detection with a corresponding 95% confidence interval.


This module is an improved generalization of the MPN approach to compare the accuracy of two microbiological methods. It compares their probability of detecting a single organism but can also combine data from multiple species. It is also possible to specify both homogeneous (i.e., same) and heterogeneous (different) accuracies among these species.

Modules for Quantitative Methods


With this module it is possible to estimate concentration-response curves (linear, log-linear, Mitscherlich, and Michaelis-Menten), and to test for proportionality.


This module offers non-inferiority testing on the mean count for a single concentration using the Poisson distribution, non-inferiority testing across all concentrations using concentrations response curves, and estimation of concentration ranges satisfying accuracy


The precision module allows the estimation of repeatability and of intermediate precision with their corresponding 95% confidence intervals. Furthermore, it performs non-inferiority testing on intermediate precision.