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for identification of e coli single streak rapid differentiation series hicrome m1295 m1295i tm hicrome e coli agar for the chromogenic detection enumeration and confirmation of escherichia coli in food and water samples hicrome e.coli agar is recommended for the detection enumeration confirmation of escherichia coli in food and water samples this medium can also be used in membrane filtration technique quality control appearance of powder gelling colour and clarity reaction beige coloured homogeneous free flowing powder firm comparable to 1.2 of m1295 or 1.5 of m1295i agar gel light yellow coloured clear to slightly opalescent gel forms in petri plates reaction of 3.66 w/v aqueous solution is ph 7.2 ± 0.2 at 25°c at 44 c for 18-24 hours organisms atcc e coli 25922 s serotype enteritidis 13076 s aureus 25923 growth luxuriant luxuriant inhibited colour of colony bluish green colourless o composition ingredients casein enzymic hydrolysate peptone special bile salts mixture disodium hydrogen phosphate sodium dihydrogen phosphate sodium chloride x-glucuronide agar m1295 grams/litre 14.00 5.00 1.50 1.00 0.60 2.40 0.075 12.00 m1295i grams/litre 20.00 1.50 0.075 15.00 cultural response cultural characteristics observed after an incubation final ph at 25°c 7.2 ± 0.2 formula adjusted standardized to suit performance parameters directions suspend 36.58 grams in 1000 ml distilled water heat to boilling to dissolve the medium completly sterilize by autoclaving at 15 lbs pressure 121°c for 15 minutes cool to 50°c and pour into sterile petri plates references 1 anderson j.m and baird-parker a.c 1975 j appl bact 39:111 2 hansen w and yourassawsky e 1984 j clin microbiol 20:1177 storage and shelf-life store at 2-8°c in tightly capped container use before expiry date on the label principle and interpretation hicrome e coli agar is based on tryptone bile agar to detect escherichia coli in foods 1 where recovery of escherichia coli is faster more reliable and accurate most of the escherichia coli strains can be differentiated from other coliforms by the presence of enzyme glucuronidase which is highly specific for escherichia coli 2 the chromogenic agent x-glucuronide used in this medium helps to detect glucuronidase activity escherichia coli cells absorb x-glucuronide and the intracellular glucuronidase splits the bond between the chromophore and glucuronide the released chromophore gives bluish green colouration to the colonies s serotype enteritidis e coli and total coliforms casein enzymic hydrolysate and peptone special provide the essential growth nutrients to the organisms bile salts mixture inhibits gram-positive organisms sodium chloride and phosphates maintain osmotic balance and buffering action respectively dry the surface of the medium before use dilute food samples 1:5 or 1:10 with 0.1 w/v sterile peptone water m028 and homogenize in a blender or a stomacher pipette 0.5 ml or 1.0 ml of the homogenized food sample on to the plate and spread with a sterile glass spreader incubate the plates at 30°c for 4 hours and then at 44°c for 18 hours e coli m1295 hicrome e coli agar single streak rapid differentiation series hicromeveg tm freedom from bse tse worries 6 hicrome e coli agar m1295 m1295i is also available as hicrome e coli hivegtm agar mv1295 mv1295i wherein all the animal origin nutrients have been replaced by vegetable based nutrients.

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for identification of e coli single streak rapid differentiation series hicrome m1571 tm hicrome m-tec agar for detection of thermotolerant escherichia coli in water by the membrane filtration technique hicrome m-tec agar is recommended by the u.s environmental protection agency usepa for detection of thermotolerant escherichia coli in water by the membrane filtration technique quality control appearance of powder gelling light yellow coloured homogeneous free flowing powder firm comparable with 1.5 agar gel light amber coloured clear to slightly opalescent gel forms in petri plates reaction of 4.56 w/v aqueous solution is ph 7.3 ± 0.2 at 25°c cultural characteristics observed after an incubation at 44.5 ± 0.2°c for 22 24 hours growth good to luxuriant inhibited good good colour of colony purple magenta colourless-tan colourless-light brown composition ingredients proteose peptone yeast extract lactose sodium chloride dipotassium phosphate monopotassium phosphate sodium lauryl sulphate sodium deoxycholate chromogen agar final ph at 25°c 7.3 ± 0.2 formula adjusted standardized to suit perforance parameters grams/litre 5.0 3.0 10.0 7.5 3.3 1.0 0.2 0.1 0.5 15.0 colour and clarity reaction cultural response organisms atcc e coli 25922 e faecalis 29212 k pneumoniae 13883 p mirabilis 25933 directions suspend 45.6 grams in 1000 ml distilled water heat to boiling to dissolve the medium completely sterilize by autoclaving at 15 lbs pressure 121°c for 15 minutes cool to 45°c and pour into sterile petri plates references 1 u.s environmental protection agency 2002 method 1603 publication epa-821-r-02-023 2 dufour strickland and cabelli 1981 appl environ microbiol 41 1152 principle and interpretation hicrome m-tec agar is a chromogenic medium used for detection and enumeration of thermotolerant e coli tec in water by membrane filtration technique 1 it is a modification of the m-tec agar developed by dufour 2 the modified medium contains the chromogen x-glucuronide that is cleaved by the enzyme b-glucuronidase to yield glucuronic acid produced by e.coli strains this selectively imparts a purple-magenta colour to the colonies of e coli proteose peptone and yeast extract provides essential nutrients lactose is the fermentable carbohydrate sodium chloride maintains osmotic equilibrium monopotassium phosphate and dipotassium phosphate provide strong buffering system to control the ph in the presence of fermentative action sodium lauryl sulphate and sodium deoxycholate make the medium more selective by inhibiting gram positive bacteria storage and shelf-life store at 2 8°c in tightly capped container use before expiry date on the label escherichia coli m1571 hicrome m-tec agar 7 thermotolerant e coli

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