Definition of agar in English:


(also agar-agar)


  • [mass noun] A gelatinous substance obtained from certain red seaweeds and used in biological culture media and as a thickener in foods.

    • ‘Starved border cells plated on to nutrient agar demonstrated no sign of contamination after 48 h incubation.’
    • ‘All children are curious about the texture of the blood agar, and many have indicated an interest in touching it.’
    • ‘The three bacterial species used to initially inoculate treatments grew readily on nutrient agar.’
    • ‘So things like common salt, sugar and agar have to be documented even though harmless.’
    • ‘Precipitation of a peptide in the top agar with subsequent release of amino acids can also lead to confounding results.’
    • ‘You can find agar flakes, a seaweed-derived thickener, in natural food stores.’
    • ‘To study these bacteria he grew them in glass Petri dishes on a substance called agar, in his laboratory.’
    • ‘Numbers of bacteria were measured using soil dilution plating on soil extract agar media.’
    • ‘A fluorescence image of 12 tobacco plantlets growing on agar within a covered Perspex Petri dish.’
    • ‘The gelatinizing agent was a Japanese seaweed called agar-agar, commonly found in organic stores.’
    • ‘Seeds are scraped off into sterilized flasks containing nutrient agar-agar.’
    • ‘For the quinoa and verjus gelee salad: In a pot, combine verjus, sugar and agar-agar; let sit for 10 minutes then bring to a boil.’
    • ‘The neonate larvae were reared individually on plant material in 30 ml plastic cups lined with agar to keep the plant material fresh.’
    • ‘The strains were maintained on nutrient agar slants before used.’
    • ‘Some alternatives which produce results similar to gelatin are agar-agar, carrageenan, tapioca, sago, guar gum, pectin, and rennet.’
    • ‘These are made by applying to the face a soft material such as wax, plaster, or, in modern times, agar, a vegetable gelatine.’
    • ‘In making their nests, the birds cement a scaffolding of tiny twigs together with a sticky substance which has been variously identified as coming from regurgitated seaweed, such as agar-agar, or as being simply the birds' own saliva.’
    • ‘Suspected colonies were cultured overnight on Columbia blood agar.’
    • ‘Seeds were surface-sterilized and sown on GM agar plates lacking sucrose.’
    • ‘Arabidopsis plants were grown on agar containing a complete mineral complement and various concentrations of selenate and sulphate.’


Early 19th century: from Malay.