Method development and validation

When standard methods are insufficient, we develop and validate product-specific methods (e.g.,Colony Forming Unit (CFU) enumeration and contamination testing) that stand up to regulatory scrutiny and deliver reliable data your stakeholders and clients can trust.

CFU method validation

Why a CFU method validation matters

Standard CFU enumeration methods are often insufficient for novel products or complex matrices. When methods require validation, off-the-shelf protocols must be adapted or rebuilt from the ground up to ensure accurate, reproducible results.

Developing and validating your CFU method before routine testing helps you during regulatory submissions and ensures stable, reproducible results batch after batch.

CFU method validation parameters

Precision (repeatability)
Precision evaluates the consistency of CFU results when the same sample is analysed repeatedly under identical conditions. It demonstrates that the method produces reproducible microbial counts with minimal variation.

Linearity
Linearity demonstrates that the method provides CFU counts that are proportional to the concentration of viable microorganisms, ensuring reliable enumeration over a range of microbial concentrations.

Recovery
Recovery assesses the ability of the method to recover and enumerate viable microorganisms from the sample matrix. It demonstrates that the analytical procedure does not result in significant loss of microorganisms during sample preparation or analysis.

Accuracy
Accuracy evaluates the ability of the method to produce representative CFU counts by ensuring that sample preparation and serial dilution do not introduce bias.

Specificity
Specificity demonstrates that the method selectively detects and enumerates the target microorganism in the presence of sample components or other microorganisms. This ensures that the reported CFU count accurately represents the organism of interest.

Before deciding on a method validation, ask yourself:

• Do I need confidence that my CFU method produces reliable results?
• Will the method be used to support regulatory submissions or quality documentation
• Am I introducing a new product, microorganism, or sample type?
• Have I changed my sample preparation or analytical procedure?
• Do I need to demonstrate that my method is precise, accurate, and fit for purpose?
• Will the results be used to support manufacturing, stability, or product claims?

A fit-for-purpose method validation starts with clearly defining your validation needs.

Contamination method validation

Complex biological products containing viable microorganisms require carefully validated contamination methods to ensure reliable detection of microbial contaminants without interference from the product itself.

Why a contamination method validation matters

Unlike conventional food or environmental samples, microbial products can interfere with standard contaminant detection methods. The active microorganism, formulation ingredients, or sample matrix may suppress contaminant growth, reduce recovery, or generate false results. Method validation demonstrates that the selected method is fit-for-purpose and can reliably detect the contaminant of interest in your specific product matrix. This is particularly important for matrices that fall outside the scope of existing ISO validations, such as microbial biopesticides.

Contamination method validation parameters

Recovery
Demonstrates that the contaminant of interest can be recovered from the product matrix at relevant concentrations and reliably detected following sample preparation using the chosen method.

Specificity
Confirms that the method selectively detects the target contaminant in the presence of product matrix components, including the active microorganism(s), without interference or false-positive detection, even when the target organism may exhibit morphological variability under challenging matrix conditions.

Matrix suitability (fit-for-purpose)
Verifies that the selected method performs reliably in the context of the specific product matrix. Although many ISO methods are validated for food and feed applications, biopesticide formulations containing high concentrations of viable microorganisms may require additional validation to demonstrate suitability under real testing conditions.

What this service delivers

---

When you need validated methods