PURPOSE OF USING CHROMOGENIC CULTURE MEDIA
Dehydrated media serves as a nutrient system for the cultivation of microorganisms. However, the aforementioned role is just one. By adding chromogenic substrate, differentiation and selection of microorganisms becomes more convenient.

HOW DOES IT WORK
Chromogenic culture media contains nutrients such as peptones, amino acids, yeast extract, minerals and vitamins, as well as inhibitors and solidifier e.g. agar and Chromogenic mixtures (chromogens) depending upon each medium. The chromogenic mixture contains chromogenic substrates as Salmon -GAL, X-Gal, X-glucuronides, etc. Certain enzymes, produced by some bacteria, cleave these substrates, resulting in the different colouration of certain bacterial colonies.

BENEFITS
1.  Majorly the chromogenic is known for its rapidness, accuracy and simplicity involved during diagnosis.
2.  The chromogenic saves time and labour work. When compared with traditional methods, the chromogenic deliver results in shorter time for both negatives screens & presumptive positives. Some chromogenic culture media gives confirmed results within 24 hours
3.  Mostly, the result interpreted from chromogenic media does not require further testing and eliminates the need of subculture and further biochemical test for identification pathogenic agent.
4.  On a single medium, one can identify more than one organism. This is the reason for the chromogenic being so cost effective.

CHROMOGENIC INDEXING

1. TM 1197|CHROMOGENIC CANDIDA AGAR SYMBOL CULTURE NAME ATCC APPEARANCE OF COLONY A Candida albicans 10231 Light green B Candida glabrata 2001 Light white to purple C Candida tropicalis 1369 Blue-Metallic Blue D Candida Krusei 34135 Purple-Pink

2. TM 1339|CHROMOGENIC E.COLI AGAR SYMBOL CULTURE NAME ATCC APPEARANCE OF COLONY A Escherichia coli 25922 Bluish green B E. aerogenes 13048 Colourless

3. TM 1858|CHROMOGENIC COLIFORM AGAR SYMBOL CULTURE NAME ATCC APPEARANCE OF COLONY A Escherichia coli 25922 Dark blue to violet colonies B Citrobacter freundii 8090 Pink to red colonies C Salmonella enteritidis 13076 Colourless colonies D E aerogenes 13048 Pink to red colonies

4. TM 1199|CHROMOGENIC UTI AGAR SYMBOL CULTURE NAME ATCC APPEARANCE OF COLONY A Escherichia coli 25922 Pink- Purple B Enterococcus faecalis 29212 Blue C Staphylococcus aureus 25923 Cream yellow D Pseudomonas aeruginosa 27853 Colourless (greenish pigment may be observed) E Klebsiella pneumoniae 13883 Bluish Purple

Complete list of Chromogenic Culture Media: Click Here