Chromogenic Media Features

Reinventing the standard for culture-based food testing

 

While validated and robust, traditional culture-media workflows are time-consuming and resource intensive, requiring a dual-enrichment and dual-plating approach that spans several days from sample collection to final result. This limits workflow productivity, efficiency and throughput.

 

Food safety labs looking to optimize testing should therefore invest in alternative technologies that offer faster, more streamlined workflows.

Chromogen technology – How does it work?

The evolution of rapid culture media-based methods has been made possible by the development of chromogenic media, which contain soluble colorless molecules called chromogens. Chromogens are composed of two parts: 

  • A substrate (which is the target of a specific enzymatic activity of the microorganism)
  • A chromophore

When the bond between the substrate and chromophore is split by a specific enzyme, produced by the target microorganism, chromophore is released. In its unconjugated form, the chromophore expresses a distinctive color. Due to reduced solubility, chromophore forms a precipitate that imparts unique color to the colony - allowing for quick, clear detection of the target, even against background growth. 

 

Use of a single chromogenic medium, rather than multiple selective media, speeds up overall time-to-result when compared with standard methods and because of its selectivity, the number of subcultures required for further investigation is also reduced or removed, making chromogenic media less labor intensive and more economical. 

 

In the context of food and beverage testing and when compared to traditional culture-based methods, chromogenic media workflows are simpler to run and generate results in a reduced timeframe, enabling quicker actions and shorter product hold times - vital in a dynamic supply chain.

Benefits of Thermo Scientific Precis and Brilliance Agar Methods

Each component of the Thermo Scientific Precis and Brilliance Agar Methods has been expertly designed to overcome sensitivity and specificity issues without the need to carry out non-standard handling steps. 

One plate delivering right first-time results

Each workflow uses a single Brilliance chromogenic agar plate with optimized selectivity and easy-to-read, highly distinguishable colored colonies. Precis method chromogenic Brilliance Agar plates can also be used for their counter ISO method workflows.

One loop for all sample types 

Single 10 µL microbiological loop inoculation of plates for detection and enumeration workflows.

Reduced plate inoculation time

Compared to other rapid culture-based methods that require pipette inoculation.

One incubation temperature 

A single incubator temperature for enrichment and plate for streamlined laboratory operations.

One, easy confirmation step

A simple rapid (>30 minute) test to confirm Salmonella species and Listeria species/L. monocytogenes. A single, overnight plating step to confirm Cronobacter species.

For Research Use Only. Not for use in diagnostic procedures.