HiColiform™ Broth, Modified

HiColiform® Broth, Modified was designed for detection and confirmation of Escherichia coli and total coliforms from water samples using a combination of chromogenic and fluorogenic substrates. Escherichia coli can be distinguished from other coliforms by its unique ability to fluoresce in the presence of fluorogenic substrate. The fluorogenic substrate is split by enzyme ß-glucuronidase especially present in Escherichia coli.

• Appearance: Cream to yellow homogeneous free flowing powder

  Colour and clarity of prepared medium: Light yellow coloured, clear to slightly opalescent solution in tubes

  Reaction: Reaction of 1,74% w/v aqueous solution at 25 °C

  pH: 6,60 to 7,00

  Cultural response: Cultural characteristics observed after an incubation at 35 to 37 °C for 18 to 24 hours

Recommended for the detection and confirmation of Escherichia coli and total coliforms from water samples, using a combination of chromogenic and fluorogenic substrates.

The reaction is indicated by the development of a blue fluorescence under UV light. The presence of total coliforms is indicated by blue-green colourations due to the cleavage of the chromogenic substrate. IPTG amplifies enzyme synthesis and increases the activity of beta - galactosidase. Peptone provides carbon, nitrogen substances, long chain amino acids, vitamins and other essential growth nutrients and is useful for the simultaneous detection of indole production. The phosphate salts provide buffering action for rapid growth of coliforms. Sodium chloride helps to maintain the osmotic balance. Sodium lauryl sulphate makes the medium selective by inhibiting accompanying microflora, especially the gram-positive organisms.

Store between 15 to 25 °C in a tightly closed container and the prepared medium at 2 to 8 °C. Use before expiry date on the label. On opening, product should be properly stored dry, after tightly capping the bottle in order to prevent lump formation due to the hygroscopic nature of the product. Improper storage of the product may lead to lump formation. Store in dry ventilated area protected from extremes of temperature and sources of ignition Seal the container tightly after use. Product performance is best if used within stated expiry period.

Suspend 17,4 gram in 1000 ml purified/distilled water. Heat if necessary to dissolve the medium completely. Mix well and dispense in tubes or flasks as desired. Sterilise by autoclaving at 15 lbs pressure (121 °C) for 15 minutes.

Limitations:
ß-glucuronidase is present in 97% of E.coli strains, however few E.coli may be negative
Some species may show poor growth due to nutritional variations

Attention: Read the label before opening the container. Wear protective gloves/protective clothing/eye protection/ face protection. Follow good microbiological lab practices while handling specimens and culture. Standard precautions as per established guidelines should be followed while handling clinical specimens. Safety guidelines may be referred in individual safety data sheets.