Columbia Agar

KM0001 Columbia Agar is a modification of the original Columbia Agar formulation described by Ellner et al. from Columbia University and is tested in accordance with ISO 11133:2014. Columbia Agar provides a medium that is suitable for use with both defibrinated horse and sheep blood to support the growth and determining haemolytic reactions of a variety of microorganisms.

Columbia Agar with the addition of plain or chocolated blood is recommended by the UK Standards for Microbiology Investigations for various purposes, including as a standard, supplementary or primary isolation medium. Columbia agar with blood is a general-purpose, non-selective medium suitable for isolation and cultivation of most organisms including fastidious anaerobes from clinical specimens. Chocolating the blood provides a highly nutritious medium which supports the growth of a wide range of pathogens including the most fastidious organisms and is particularly useful for the cultivation of Haemophilus and Neisseria species.

Chocolate agar is the same as blood agar except that during preparation the red blood cells are lysed when added to molten agar base, which gives the medium a chocolate-brown colouration and from which the agar gets its name. As a result, cell lysis releases intracellular nutrients such as haemoglobin, haemin (X factor), and the coenzyme nicotinamide adenine dinucleotide (NAD or V factor) into the agar. These growth factors are available to fastidious organisms during growth.

Related Supplements :
Defibrinated Horse Blood, Defibrinated Sheep Blood, Horse Blood Lysed, LS0008 Staph/Strep Selective Supplement, LS0017 Neomycin Selective Supplement, LS0022 Clostridium difficle Selective SupplementLS0012 Bacitracin Selective Supplement, LS0011 Campylobacter Growth Supplement, LS0009 Campylobacter (Skirrow) Selective Supplement

Additional Information

Shelf Life (days)

Storage Temp (°C)

Dehydrated Medium Appearance

Prepared Medium Appearance

Dehydrated Medium Colour

Prepared Medium Colour

Dehydrated pH

Prepared pH

Product Description

Prepared with 5% Defibrinated Horse Blood:

Organisms Ref. No Result
Bacteroides fragilis NCTC 9343 Growth: Grey colonies
Streptococcus pyogenes NCTC 12696 Growth: White colonies with β-haemolysis
Escherichia coli NCTC 12241 Growth: Grey colonies
Streptococcus pneumoniae NCTC 12977 Growth: Grey/green colonies with α-haemolysis
Enterococcus faecalis NCTC 12697 Growth: White colonies with β-haemolysis
Staphylococcus aureus NCTC 12981 Growth: White colonies
Clostridium perfringens NCTC 8237 Growth: Grey colonies
Pseudomonas aeruginosa NCTC 12903 Growth: Grey colonies
Salmonella typhimurium NCTC 12023 Growth: Grey colonies
Listeria monocytogenes NCTC 11994 Growth: White colonies with β-haemolysis
Streptococcus agalactiae ATCC 12386 Growth: White colonies with β-haemolysis

 

Formula*

Formula * g/L
Peptones 23.0
Starch 1.0
Sodium chloride 5.0
Agar 11.0
Total 40.0
*Adjusted/supplemented as required to meet performance requirements

Preparation

Suspend 40.0g of dehydrated culture medium in 1 litre of deionised/purified water. Soak with frequent agitation for 10 minutes to completely dissolve medium. Autoclave to sterilise at 121°C for 15 minutes before cooling in a water bath to 45-50°C and aseptically add the appropriate volume of horse or sheep blood (full instructions for chocolating blood are found in the IFU). Cool to 42-46°C and add any final selective supplements if required and gently homogenize the final medium before aseptically dispensing the specified volume into appropriate sterile containers and allowing to cool.