Chromogenic Technology

How does Chromogenic Culture Media technology work? 

This technology is based on soluble colourless molecules (called chromogens), composed of a substrate (targeting a specific enzymatic activity) and a chromophore.
When the target organism’s enzyme cleaves the colourless chromogenic conjugate, the chromophore is released. In its unconjugated form, the chromophore exhibits its distinctive colour and, due to reduced solubility, forms a precipitate.

There are several advantages to this method

  • The result is very specific and distinctive.
  • colour-based differentiation method.
  • clearly distinguishable with the naked eye under normal lighting conditions. With this technique, colonies of specific microorganisms can be recognized by their colour at a glance.


Powerful colours on RambachTM Agar
Click on the picture to enlarge

  • It allows for easy differentiation of microorganisms without the complex and costly traditional detection procedures employed in traditional agar testing techniques (No subcultures).
  • By saving time and labor, it increases the efficiency of laboratory testing.
  • By shortening the timeframe for identifying pathogens, it helps to prevent the spread of infections.

CHROMagar™, Rambach™, AquaCHROM™ are trademarks created by Dr. A. Rambach.
All pictures of our products are CHROMagar property and should not be used without our acceptance.

Dr. Alain Rambach
Pioneering Scientist

  • 1967
    Following his studies at Ecole Polytechnique in Paris, Alain Rambach joins the Pasteur Institute where he works with professor François Jacob, Nobel Prize winner in genetics.
  • 1973
    On completing his thesis in bacterial genetics, and in face of strong opposition from the scientific community. Dr. Rambach embarks on his research in gene manipulation. Eventually this field -becomes known as genetic engineering.
  • 1976
    After two years at Stanford University as a postgraduate in biochemistry, he returns to France and joins the Pasteur Institute as one of the leading scientists in the field of genetic engineering.
  • 1979
    In an unrelated field, he pioneers, invents and patents a system for detecting E.coli bacteria by 'chromogenic differentiation' culture media.

  • 1980
    Dr. Rambach establishes the firm Genetica as a joint venture with Rhône Poulenc. Genetica has been involved in genetic engineering and has become one of the leading R&D companies in the field of pharmaceutical fermentation process. When Rhône Poulenc integrates Genetica into its structure, Dr. Rambach decides to pursue his goal and devotes his talent and energy to developing another invention.
  • 1989
    He patents a 'chromogenic' system for detection of the Salmonella pathogen, known as Rambach Agar. This is the first commercially available chromogenic culture medium.
  • 1993
    Dr. Rambach founds CHROMagar Microbiology.
  • 1993 – Present
    Dr. Rambach heads Research and Development at CHROMagar.