Anaerobic HiVeg™ Agar w/o Dextrose

Principle And Interpretation

Anaerobic HiVeg™ Agar w/o Dextrose is prepared by using vegetable peptones in place of animal based peptones which make the media free of BSE/TSE risks. Anaerobic HiVeg™ Agar without Dextrose is devoid of dextrose (1) and is used for carbiohydrate fermentation studies and for studies of haemolytic activity of Clostridia, Streptococci and other organisms. HiVeg™ hydrolysate is the only source of nutrient present. It provides nitrogen and carbon source, long chain amino acids, vitamins and other essential nutrients. Other peptones, rich in carbohydrates like yeast extract or soya peptone are not used in this medium as this medium favours distinct haemolytic reactions. Addition of sodium thioglycollate and sodium formaldehyde sulphoxylate create conditions necessary for cultivation of anaerobic bacteria which is indicated by methylene blue dye present in the medium. Sodium chloride maintains osmotic equilibrium. For haemolytic tests anaerobic blood agar plates may be prepared in one of the following ways; Sterile blood in about 0.7 ml amount and small inoculum may be mixed with 25-50 ml of cooled agar and mixture is poured into the Petri plate filling it up to 3/4. After solidification the lid is replaced with Brewer Anaerobic Petri plate cover. An ordinary sterile Blood Agar plate (made from Blood Agar Base or Tryptone Soya Agar) may be streaked with a culture. Melted and cooled Anaerobic Agar without Dextrose is then poured over the Blood Agar to provide the proper depth. After solidification the lid is replaced with anaerobic Petri plate cover. The anaerobic cover should not rest on the Petri plate bottom: its inner ridge should seal the agar, and the medium within the ridge should not touch the cover at any point. The medium should be cherry red in colour after addition of blood.