Category: G

Dorset’s egg medium incorporating glycerol, to aid cultivation of Myco. tuberculosis var. hominis.  

Nutrient broth containing 5 – 7 per cent glycerol, used mainly for culture of myobacteria.  

Nutrient agar plus 5 – 8 per cent glycerol, of particular use for the cultivation of mycobacteria.  

Germicide capable of the (slow) destruction of spore-bearing organisms in addition to vegetative bacteria. Marketed as Cidex, glutaraldehyde is diluted to a 2 per cent solution in dilute sodium bicarbonate to give the reaction (pH 7.5 – 8.5) for most effective use. Action is best in the absence of organic matter, and the germicide is…

Nutrient broth with high glucose and serum levels, used as a protective medium for the suspension of delicate bacteria preparatory to freeze-drying.  

Bacteriological nutrient broth plus glucose, acting as both nutrient and reducing agent, usually at 0.1 to 1.0 per cent.  

Nutrient agar plus 0.1 -1.0 per cent glucose, used for stab cultures of anaerobic organisms.  

Characterization test for coliform organisms, a positive result showing ability of the culture to oxidize potassium gluconate to 2 keto- gluconate. All Enterobacter species are positive; only a few others exhibit the trait.  

Gelatin was used to solidify culture media prior to the advent of agar-agar. Its property of liquefying at around 28°C limited the possibilities of use.  

The possession of proteolytic properties is an important secondary characteristic of many species of bacteria (especially enterobacteria and Clostridia) and is determined by the ability of the culture to hydrolyse gelatin. In the traditional method a nutrient gelatin butt is inoculated and incubated, hydrolysis being indicated by liquefaction of the medium. Up to 14 days…