Rapid Viability and Enumeration by Flow Cytometry for Probiotics and LBPs

FCM provides a much faster, orthogonal assessment that supports day-to-day iteration. While CFU plating remains essential for historical data and standard release criteria, it takes days and misses VBNC populations. FCM analyzes individual cells in minutes, differentiating live, dead, and injured populations based on membrane integrity. It provides rapid viability percentages that can be correlated back to your CFU workflows, significantly accelerating formulation screening and bioprocess decisions.

To construct an accurate technical proposal and begin method setup, we ideally need to know the target strain(s) or species, the intended sample matrix (e.g., washed cells, lyophilizate, complex fermentation broth), any known aggregation tendencies, and whether you require bridging studies to existing release methodologies (like specific CFU plating protocols).

Yes. For single strains or simple evaluations, universal live/dead dyes (e.g., SYTO 24/PI) are highly effective. For multi-strain commercial blends where you need to track the viability of a specific targeted strain against a complex background, we can achieve specificity by integrating fluorophore-conjugated primary and secondary antibodies into the FCM gating strategy.

Your final report will detail the finalized sample preparation methodology, the documented gating logic (supported by representative bivariate cytograms), absolute viability percentages and event counts, batch consistency evaluations (if applicable), and optionally, the statistical correlation graphs demonstrating how the FCM data bridges to your standard CFU outputs.