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  • Alkaline Peptone Water is generally used as an enrichment medium in the isolation of Vibrio spp. from faeces. The high pH of the medium inhibits most enteric organisms for at least 24 hours. The medium is heavily inoculated with faeces and after not more than 8 hours incubation a loopful from the top of the medium is sub cultured onto TCBS Agar. This enrichment medium is also used for food and water testing.
  • This is a medium supporting a wide range of organisms. It conforms to the requirements of the United States Pharmacopeia (USP) for antibiotic sensitivity testing of pharmaceutical products. As previously stated Antibiotic Medium No. 1 is used in the performance of antibiotic assays. This medium is prepared according to the specifications detailed in the USP. The use of this medium assures well-defined inhibition zones of the test organisms. Nutrients and growth factors are supplied by peptic digest of animal tissue, casein hydrolysate, yeast extract, and beef extract. Glucose is a carbon source.
  • This is a medium supporting a wide range of organisms. It conforms to the requirements of the United States Pharmacopeia for antibiotic sensitivity testing of pharmaceutical products. Antibiotic Assay Medium No.32 is a modification of Antibiotic assay medium No.1. (E & O BM4710). This medium is used to develop inoculum of Bacillus subtilis for antibiotic assay used in the test for assaying by the plate assay method.  Nutrients and growth factors are supplied by peptic digest of animal tissue, casein hydrolysate, yeast extract, and beef extract. Glucose is a carbon source.
  • This is a medium supporting a wide range of organisms. It conforms to the requirements of the United States Pharmacopeia for antibiotic sensitivity testing of pharmaceutical products. Antibiotic Assay Medium  No. 8 is recommended for preparing inoculum of Bacillus subtilis to be used as a test  for assaying Vancomycin by plate assay method.
  • Bile Aesculin Medium is generally used for the differentiation and presumptive identification of Group D streptococci (enterococci). Enterococci hydrolyse aesculin forming, amongst other products, aesculetin which in turn combines with Ferric ammonium citrate producing a dark brown or black complex. The presence of Bile salts in the medium inhibits gram positive organisms other than enterococci. The medium can also be used for the presumptive identification of certain organisms within the Enterobacteriaceae group such as Klebsiella spp., Enterobacter spp., etc.
  • Bile Aesculin Agar Bile Aesculin Medium is generally used for the differentiation and presumptive identification of Group D streptococci (enterococci). Enterococci hydrolyse aesculin forming, amongst other products, aesculetin which in turn combines with Ferric ammonium citrate producing a dark brown or black complex. The presence of Bile salts in the medium inhibits gram positive organisms other than enterococci. The medium can also be used for the presumptive identification of certain organisms within the Enterobacteriaceae group such as Klebsiella spp., Enterobacter spp., etc.
  • This is a very nutritious general-purpose medium suitable for the isolation of most organisms including many fastidious anaerobes. It is particularly recommended for streptococci and neisseria.
  • Brucella Broth was developed to cultivate Brucella spp. from a wide variety of clinical samples but it is also widely used as a general enrichment broth for both fastidious and non-fastidious organisms.
  • This is a modification of the original Nitrate Reduction Broth which is generally used as one of a series of identification tests for the enterobacteriaceae group of organisms. In addition to allowing the testing of Nitrate Reduction this formulation also contains Agar making it possible to concurrently determine motility. The medium is recommended for use in the confirmatory testing of Clostridium perfringens in water samples. The medium is inoculated by “stabbing” the test organism into the medium, using an inoculating needle or straight wire, and after appropriate incubation motility is demonstrated by diffusion of the organism from the line of inoculation into the medium. The Nitrate Reduction Test is a test for the presence of the enzyme nitrate reductase which, in the presence of an appropriate electron donor, reduces nitrate to nitrite. Following incubation “Nitrate Reagent” is added to the medium and a positive reaction is indicated by the formation of a red colour. For full details of the test method reference should be made to appropriate publications.
  • Cetrimide Agar is intended primarily for use in the isolation of Pseudomonas aeruginosa from pharmaceutical products and is recommended by the United States Pharmacopoeia for this purpose. The medium is made selective by the addition of cetrimide to inhibit the growth of most other organisms while allowing Pseudomonas aeruginosa/ and other Pseudomonas spp. to develop a classical colonial appearance, producing green pigmentation and fluoresce when examined under ultra violet light.
  • CHROMagar™ Candida Plus is the first chromogenic isolation medium for the detection and differentiation of C. auris in addition to other major clinical Candida spp. such as C. albicans, C. tropicalis, C. glabrata. Candida spp. are yeasts involved in various infections called Candidiasis. These infections can be severe with significant morbidity in nosocomial infections or in immunocompromised patients. Although C. albicans is still the main species involved, the use of antifungal agents has given rise to other species such as C. tropicalis, C. krusei and C. glabrata. In 2016, WHO added C. auris to this list with over 90 % of strains resistant to fluconazole. CHROMagar™ Candida Plus allows for the recognition of minor candida species in a mixed population containing the predominant species, thereby allowing patient specific treatment plans to be formulated at the earliest possible opportunity. Most bacterial species will be inhibited due to the inclusion of the selective mix: C. albicans Green colonies C. tropicalis Metallic blue colonies C. glabrata Mauve to pink colonies C. auris Light blue colonies with blue halo E. coli Inhibited Limitations The final identification must be confirmed by biochemical tests or by mass spectrophotometry (eg MALDI-TOF). These can be done directly from the suspicious colonies observed on the medium.
  • PP3038

    Colorex STEC

    COLOREX™ STEC is a chromogenic medium(1) for the detection of enterohaemorrhagic E. coli (including serotypes O26, O111 & O157). Over the past few years there has been an increase in the number of food poisoning outbreaks where non-O157 Shiga toxin producing E. coli (STEC) have been shown to be etiological agent. The medium contains several selective agents to reduce the level of background flora from the specimen or food sample. Positive STEC colonies exhibit a mauve colouration enabling easy interpretation amongst other Gram negative bacteria that will exhibit blue or colourless colonies, if they are able to grow on the medium. Gram positive bacteria will be inhibited.
  • Colorex™Acinetobacter MDR is a chromogenic medium for the detection of multi-drug resistant (MDR) Acinetobacter spp. Positive colonies exhibit a distinct red colouration with a pale grey centre enabling easy interpretation amongst blue, violet or colourless colonies that may be produced by other Gram –ve bacteria. Gram +ve bacteria and yeast are inhibited on this medium. Limitations: 1.  Some Pseudomonas, Stenotrophomonas and Burkholderia spp. may form pale red colonies on this medium but are readily distinguishable due to differences in colonial morphology compared to the Acinetobacter spp. An oxidase test will readily differentiate any Pseudomonas spp. 2. Some Enterobacteriaceae isolates may form blue colonies on this medium. 3. Definitive MDR characterisation may require additional antibiotic susceptibility testing.
  • Colorex™ Campylobacter is a chromogenic media for the isolation and presumptive identification of Campylobacter spp, from clinical specimens and food samples. Any presumptive Campylobacter colonies will produce a red colouration whilst most other organisms will be inhibited. Typical colour reactions are as follows – Campylobacter jejuni – Red colonies; Campylobacter coli – Red colonies; Campylobacter lari – Red colonies; Other Gram –ve bacteria – Blue colonies or inhibited; Gram +ve bacteria & yeasts – Inhibited. Presumptive positive Campylobacter colonies must be confirmed using serological and biochemical techniques according to the method / procedure being followed.
  • In recent years there has been an increase in the number of immuno-compromised patients, which has in turn led to an increased rate of infections associated with Candida species. There were 2151 reported cases of candidaemia in 2016 with C.albicans accounting for 42%, C.glabrata for 25%, C.parapsilosis for 9% and C.tropicalis for 3% of infections in England, Wales and Northern Ireland.(1) COLOREX™ Candida was formulated specifically for the detection and isolation of clinically significant Candida spp. by means of colonial colour and morphology within 48hrs. COLOREX™ Candida allows for the recognition of a minor Candida population within a mixed population as well as the pre-dominant species thereby allowing for a patient specific treatment plan at the earliest possible opportunity. Most bacterial species will be inhibited due to the inclusion of chloramphenicol. C.albicans – Green colonies C.tropicalis – Metallic blue colonies C.glabrata – Mauve to pink colonies C.krusei – Large fuzzy pink colonies Limitations Definitive identification requires additional testing of isolates (e.g. MALDI-TOF). C.glabrata and C.parapsilosis cannot be readily distinguished on this particular medium. C.dubliniensis will form dark green colonies on COLOREX™ Candida so additional testing is required to confirm presence in the specimen. C.auris isolates will grow on this medium but the colony colour may vary from white to pale purple/pink so further testing will be required to confirm identification.
  • This is a selective chromogenic medium for the detection of Malassezia spp., especially M.restricta and M.globosa, in veterinary or clinical specimens. Malassezia spp. is a commensal organism in humans and animals that can cause severe dermatitis or otitis infections. The medium is supplemented with Glycerol and Tween 40 to enhance the in-vitro growth of Malassezia spp. due to the complex lipid requirements of these yeasts. Appearance and differentiation of Malassezia spp. is readily apparent by the distinctive colonial colours allowing for differentiation from Candida spp. in specimens. The inclusion of chloramphenicol ensures the inhibition of bacterial species during incubation of specimens.
  • Colorex™ MRSA is a chromogenic medium for the selective isolation of Methicillin-Resistant Staphylococcus aureus (MRSA). The medium can be used for the routine screening of clinical specimens for MRSA from a variety of sampling sites such as the nose, throat and groin. The medium incorporates a nutritious peptone base medium and a number of selective agents to inhibit most Gram-negative and Gram-positive bacteria as well as yeasts and moulds. The chromogenic detection of specific enzyme activity leads to the formation of pink/mauve colonies indicating MRSA (including low level resistant and hetero-resistant strains) following incubation at 37°C for 18-24 hours. Other organisms, if present are indicated by blue or colourless colonies. Any presumptive isolates must be confirmed using serological and/or biochemical techniques available to the laboratory. The use of this chromogenic medium does not diminish the requirement for conventional antimicrobial susceptibility tests for the confirmation of methicillin resistance. Limitations: 1. S.aureus strains that possess a low MIC to the selective agent present in the medium but are mec A negative may form colonies on the medium. 2. Some MRSA strains may form typical colonies surrounded by a matte halo. The formation of the halo serves no diagnostic function. 3. Certain methicillin-resistant coagulase-negative staphylococci (CNS) may produce characteristic colonies. In some cases differentiation may be achieved by examination of the colour of these colonies, as they may be considerably darker in colour (bluish purple to a very dark pink/magenta). 4. Certain bacterial species other than staphylococci may produce colonies with a characteristic colour.
  • Colorex™ MRSA is a chromogenic medium for the selective isolation of Methicillin-Resistant Staphylococcus aureus (MRSA). The medium can be used for the routine screening of clinical specimens for MRSA from a variety of sampling sites such as the nose, throat and groin. The medium incorporates a nutritious peptone base medium and a number of selective agents to inhibit most Gram-negative and Gram-positive bacteria as well as yeasts and moulds. The chromogenic detection of specific enzyme activity leads to the formation of pink/mauve colonies indicating MRSA (including low level resistant and hetero-resistant strains) following incubation at 37°C for 18-24 hours. Other organisms, if present are indicated by blue or colourless colonies. Any presumptive isolates must be confirmed using serological and/or biochemical techniques available to the laboratory. The use of this chromogenic medium does not diminish the requirement for conventional antimicrobial susceptibility tests for the confirmation of methicillin resistance. Limitations: 1.  S.aureus strains that possess a low MIC to the selective agent present in the medium but are mec A negative may form colonies on the medium. 2. Some MRSA strains may form typical colonies surrounded by a matte halo. The formation of the halo serves no diagnostic function. 3. Certain methicillin-resistant coagulase-negative staphylococci (CNS) may produce characteristic colonies. In some cases differentiation may be achieved by examination of the colour of these colonies, as they may be considerably darker in colour (bluish purple to a very dark pink/magenta). 4. Certain bacterial species other than staphylococci may produce colonies with a characteristic colour.
  • Recent developments in culture media have given rise to the use of chromogenic substrates as a means of differentiating bacteria particularly among the coliform group of organisms. Colorex™ UTI has been developed primarily for use in the examination of urine specimens with the aim of simplifying the differentiation and presumptive identification of the main organisms, gram negative and gram positive, usually found in Urinary Tract Infections. It can however be used to differentiate organisms in other types of clinical specimens. The distinctive colonial colouration of the various species can reduce the need for additional follow up testing allowing many positive results to be issued within 24 hours of receipt of the sample. If necessary an Indole test for confirmation of Escherichia coli and TDA test for Proteus spp. can be performed directly from the medium.
  • This is a chromogenic medium for the isolation and presumptive identification of Staphylococcus aureus. Mauve colonies indicate Staph aureus following incubation (18 – 24 hours) at 37°C, other organisms, if not inhibited, are indicated by blue or colourless colonies. Studies have suggested that this media has a specificity and sensitivity of 99.4% and 95.5% respectively (Gaillot et al 2000).
  • BM0090

    Columbia Agar

    Columbia Agar is a nutritious general-purpose basal medium capable of supporting the growth of most micro-organisms, including many fastidious organisms that do not require blood. However when further enriched with Sterile Blood, which can be “chocolated” if required, the medium is generally used for the isolation of most clinically significant pathogens.  The medium can be made selective for various groups of organisms by the addition of a range of antimicrobial supplements. This formulation complies with the Harmonized USP/EP/JP.
  • A basic general-purpose blood free medium, capable of supporting the growth of most micro-organisms, including many fastidious organisms that do not require blood.
  • PP0400

    DNase Agar

    DN'ase Medium DNase Agar is used primarily in clinical laboratories to differentiate Staphylococcus aureus from other Staphylococci based on deoxyribonuclease activity. Following incubation of the plate and confirmation of a pure growth of Staphylococci, the surface of the medium is covered with a small quantity of 1M Hydrochloric Acid to precipitate the DNA. Staphylococcus aureus produce DNase enzymes that hydrolyse DNA resulting in a clear area around the colonies, described as being DNase positive, whereas coagulase negative Staphylococci do not produce clearing. NB: As with most tests of this type a positive result should not be taken in isolation and other appropriate tests, e.g. Coagulase Test, Latex Agglutination etc, should be carried out.
  • This medium is intended for use in sterility testing of substances in accordance with the United States Pharmacopoeia and European Pharmacopoeia. It is a general purpose medium for the cultivation of both fastidious anaerobic and aerobic micro-organisms. Sodium Thioglycollate and L-cystine are included to reduce the medium to ensure anaerobiosis and to inactivate mercury and other heavy metallic compounds. A small amount of agar is added to further reduce the update of oxygen. However, in the event of oxidation, the medium will turn pink due to the presence of the resazurin. Providing only 30% of the medium has turned pink, the Eh may be restored by heating the medium (once only) in a boiling water bath.
  • LB media formulations have been an industry standard for the cultivation of Escherichia coli as far back as the 1950s. These media have been widely used in molecular microbiology applications for the preparation of plasmid DNA and recombinant proteins. Vitamins and certain trace elements are provided by yeast extract. Sodium ions for transport and osmotic balance are provided by sodium chloride. Tryptone is used to provide essential amino acids to the growing bacteria.
  • LB media formulations have been an industry standard for the cultivation of Escherichia coli as far back as the 1950s. These media have been widely used in molecular microbiology applications for the preparation of plasmid DNA and recombinant proteins. This medium has the addition of carbenicillin at 100mg/L for use with transformed cells harbouring selection plasmids containing carbenicillin resistance genes. Peptides and essential amino acids are provided by tryptone. Vitamins and certain trace elements are provided by yeast extract and sodium chloride provides osmotic balance.
  • LB media formulations have been an industry standard for the cultivation of Escherichia coli as far back as the 1950s.These media have been widely used in molecular microbiology applications for the preparation of plasmid DNA and recombinant proteins. This media has the addition of Kanamycin at 0.05gms/L for use with Kanamycin resistant strains and cells harbouring selection plasmids containing the Kanamycin resistance gene.Peptides and peptones are provided by tryptone. Vitamins and certain trace elements are provided by yeast extract. Sodium ions for transport and osmotic balance are provided by sodium chloride. Tryptone is used to provide essential amino acids to the growing bacteria, while the yeast extract is used to provide a plethora of organic compounds helpful for bacterial growth.
  • LB media formulations have been an industry standard for the cultivation of Escherichia coli as far back as the 1950s.These media have been widely used in molecular microbiology applications for the preparation of plasmid DNA and recombinant proteins. This medium has the addition of kanamycin at 50mg/L and chloramphenicol at 34mg/L, for use with kanamycin and chloramphenicol resistant strains and cells harbouring selection plasmids containing the kanamycin and rifampicin resistance genes. Peptides, peptones and essential amino acids are provided by tryptone. Vitamins and certain trace elements are provided by yeast extract and sodium chloride provides osmotic balance.
  • Luria Bertani broth (LB Broth) is a nutrient broth primarily used for the growth and maintenance of Escherichia coli. Used as the primary propagation step for donor or recipient cells, when further work is to be performed on LB Agar.
  • Letheen Broth with Neutraliser and 1% Tween 80 is primarily intended for use in assessing the bactericidal activity of quaternary ammonium compounds and determining the phenol coefficient of cationic surfactants. It can also be used in environmental testing, particularly in areas subjected to surface disinfection. Lecithin and polysorbate 80 (Tween 80) inactivate surface disinfectants (lecithin neutralises quaternary ammonium compounds and Tween 80 neutralises phenols, formalin, hexachlorophene and in combination with the lecithin ethanol).
  • LIM Broth with 10% Serum A nutritious, selective broth medium utilising the base formulation developed by Todd and Hewitt for the enrichment of Group B Streptococci. The LIM broth is made selective by the inclusion of Colistin and Nalidixic Acid to suppress the growth of the majority of other bacteria. Serum is also included to enhance the nutritional qualities of the base medium.
  • This medium is recommended by BSI and ISO for the enumeration of viable organisms in milk and other dairy products. It can also be used as a general-purpose medium for the cultivation of most organisms, particularly those that are less fastidious in their nutritional requirements.
  • This is best described as a multi-purpose medium for differentiation of enterobacteriacae that combines three individual tests into a single medium. For use the medium is inoculated by making a single stab into the medium with a straight wire (or equivalent) using a pure culture (or discrete single colony) of the test organism. Following incubation it is recommended that the medium should first of all be examined to determine whether or not the organism is motile. The presence of motility is apparent by the organism tracking out from the line of inoculation and often turning the medium turbid. Non-motile organisms generally grow within the stab line leaving the surrounding medium clear. Urease positive organisms (e.g. Proteus spp) turn the medium bright red due to the hydrolysis of the Urea in the presence of the Phenol Red Indicator often making it difficult to determine the other parameters.Indole is tested for by layering a small amount of Indole Reagent (Erlich’s or Kovac’s appear to work equally well) onto the surface of the medium and allowed a few minutes to react. A positive result is indicated by the formation of a red line at the interface of the reagent and the medium.
  • Mueller Hinton Agar is recommended for use in the antibiotic disk diffusion method by both the European Committee on Antibiotic Sensitivity Testing (EUCAST) and the Clinical Laboratory Standards Institute (CLSI). The medium contains low levels of divalent metal cations, such as calcium and magnesium, to minimise any interference with certain antibiotic classes e.g. aminoglycosides. Starch is also present to absorb any toxic metabolites that may be formed during growth. The medium is low in thymine & thymidine content and is therefore suitable for use in testing sulphonamides and trimethoprim without the addition of blood.
  • Approved by the Clinical Laboratory Standards Institute (CLSI) in USA this medium can be considered as an alternative to Iso-Sensitest Agar for antimicrobial sensitivity testing by disc diffusion methods. It is low in Thymine and Thymidine and is therefore suitable for use in testing Sulphonamides & Trimethoprim without the addition of Lysed Blood.
  • Approved by the National Committee for Clinical Laboratory Standards (NCCLS) in USA this medium is approved for use in antimicrobial sensitivity testing by the disc diffusion method and is recommended particularly for use with the Bauer-Kirby Technique It is low in Thymine and Thymidine and is therefore suitable for use in testing Sulphonamides & Trimethoprim and controlled to ensure correct zone sizes with Tetracyline and Aminoglycoside antibiotics. It can be considered as an alternative to Iso-Sensitest Agar. This particular formulation has an additional 2% Sodium Chloride added to the medium making it suitable for the detection of resistance to Methicillin in staphylococci and it is included in the recommendations of British Society for Antimicrobial Chemotherapy (BSAC) for this purpose. It is not however recommended for testing of organisms requiring a CO2 enriched environment due to the pH effect on the medium. If incubation in a CO2 enriched environment is essential control organisms should be included to confirm that results have not been altered.
  • A selective medium for the isolation of fungi, particularly dermatophytes from clinical specimens, Mycological Agar is suitable for use in all areas of Mycology. The medium inhibits most bacteria due to the addition of Chloramphenicol which is added to reduce the risk of bacterial contamination when processing material that may be heavily contaminated particularly with Coliforms. Cycloheximide is also added to suppress the growth of yeasts and saprophytic fungi.
  • This is a general-purpose neutralising diluent used particularly in the pharmaceutical industry. Lecithin, L-histidine and Tween 80 are present to inactivate surface disinfectants such as quaternary ammonium compounds, phenols, aldehydes (including formaldehyde), hexachlorophene and ethanol. The diluent may be used in sampling surfaces and equipment (including endoscopes) to detect the presence of surviving microorganisms after disinfection. The presence of the surfactant Tween 80 also helps release adherent organisms from surfaces being tested.
  • BM0540

    Nutrient Agar

    A general purpose medium for the cultivation of organisms that are less fastidious in their nutritional requirements.  This particular formulation has additional 0.2% Agar added to provide for a firmer medium without loss of efficacy. Generally used to maintain cultures or to check the purity of subcultures from isolation media.
  • PP0690

    Nutrient Agar

    A basic general-purpose medium suitable for use in the cultivation of the less fastidious organisms particularly those that do not require the addition of blood or other enrichment.
  • A general-purpose medium for the cultivation of organisms that are less fastidious in their nutritional requirements.
  • Based on Nutrient Broth with an additional 2.5% Sodium Chloride this medium is suitable for use in the investigation of outbreaks involving Staphylococcus aureus especially MRSA. The additional Sodium Chloride inhibits most other organisms allowing the staphylococci to multiply freely even if present in small numbers. The medium is generally used as an enrichment medium in conjunction with subculture onto selective solid media as described in PHE SMI B29 issue No.6.
  • Based on Nutrient Broth with an additional 6.5% Sodium Chloride (Total Sodium Chloride content = 7%) this medium is suitable for use in the investigation of outbreaks involving Staphylococcus aureus including MRSA. The additional Sodium Chloride inhibits most other organisms allowing the staphylococci to multiply freely even if present in small numbers. The medium is generally used as an enrichment medium in conjunction with subculture onto selective solid media.
  • BM0300

    Peptone Water

    A general-purpose medium that can be used as a base for carbohydrate fermentation media. It has a high level of Tryptone and is therefore also suitable for use in Indole testing.
  • This is a base medium to which can be added selective supplements of choice for the presumptive identification and enumeration of Clostridium perfringens in food products using poured plate techniques. Sodium metabisulphite and Ferric ammonium citrate are included in the base and together provide an indicator of sulphite reaction by Clostridium perfringens, which produces black colonies on the medium.  It is recommended that this medium be used with an overlay otherwise cultures may not grow as black colonies. NB: This is a base medium only and contains no selective supplements.
  • Originally intended for use in surface counting and pour plating techniques this medium can be used as a general purpose medium for the cultivation of most organisms particularly those that are less fastidious in their nutritional requirements. Can also be used as a maintenance medium for stock cultures.
  • Chromogenic Coliform Agar (CCA) Chromogenic Coliform Agar (CCA) conforms to the ISO 9308-1 guidelines for the detection, enumeration and isolation of coliforms and more specifically Escherichia coli in water samples by the membrane-filtration technique. The colonial differentiation is provided by the chromogenic substrates, Salmon-GAL and X-glucuronide. Salmon-GAL is used for the detection of β-D-galactosidase enzymatic activity. X-glucuronide is used for the detection of β-D-Glucoronidase enzymatic activity. β-D-galactosidase, expressed by all coliforms, cleaves the Salmon-GAL substrate and producing red/pink coloured colonies. Unlike other coliforms, Escherichia coli leaves both Salmon-GAL and X-glucuronide producing a violet/blue coloured colonies. Tryptophan is used to increase detection reliability by improving the indole reaction. The peptones, sodium pyruvate and sorbitol support bacterial growth and simple recovery of sub-lethal thermally injured coliforms. Sodium di-hydrogen phosphate and di-sodium hydrogen phosphate phosphate buffer the medium and sodium chloride is used to achieve osmotic balance. The selectivity is attained by the addition of Tergitol® 7 as it inhibits the growth of Gram positive bacteria.
  • Tryptone Bile X (TBX) - Glucuronide Agar Recent developments in culture media have given rise to the use of chromogenic substrates as a means of differentiating bacteria particularly among the coliform group of organisms. This is one such medium and has been developed as a selective medium for the isolation and enumeration of Escherichia coli in food samples. Based on Tryptone Bile Agar it incorporates the chromogenic agent X-glucuronide, which detects glucuronidase activity, the same enzyme as is detected by MUG reagent. Escherichia coli can be differentiated from other coliform organisms by the presence of glucuronidase resulting in the colonies being blue/green while the other coliforms are colourless. For information on the full technical detail as to the functionality of this medium reference should be made to the many publications available.
  • This is a chromogenic medium based on CLED that has been developed to allow differentiation and presumptive identification of organisms typically found in urinary tract infections. Reduced electrolyte concentration prevents swarming of Proteus spp. A sophisticated binary chromogenic system and supplementation with tryptophan allows differentiation of Enterococcus spp. (turquoise colonies), Proteus spp. (clear colonies with a brown halo), Enterobacter spp. (metallic blue colonies), Staphylococcus spp. (white colonies), and E. coli (purple colonies).
  • Pseudomonas Agar Base with 1% Glycerol, Cephalothin, Fucidin & Cetrimide (CFC) This is a selective medium for the isolation of Pseudomonas spp primarily in food, water and environmental samples. The medium uses Magnesium and Potassium salts to enhance pigment production and is made selective by the addition of CFC supplement. The presence of blue/green or brown pigmentation or fluorescence is indicative of presumptive Pseudomonas spp. It should be noted however that further testing must be carried out to confirm the full identity of the organism.