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The Löwenstein–Jensen medium, more commonly known as LJ medium, is a growth medium specially used for culture of Mycobacterium, notably ''Mycobacterium tuberculosis''. When grown on LJ medium, ''M. tuberculosis'' appears as brown, granular colonies (sometimes called "buff, rough and tough"). The media must be incubated for a significant length of time, usually four weeks, due to the slow doubling time of ''M. tuberculosis'' (15–20 hours) compared with other bacteria. == Composition == The usual composition〔(Composition of LJ medium )〕 as applicable to ''Mycobacterium tuberculosis'' is: * Malachite green * Glycerol * Asparagine * Potato starch * Coagulated eggs * Mineral salt solution * * Potassium dihydrogen phosphate * * Magnesium sulfate * * Sodium citrate The original formulation included starch, which was later found to be unnecessary and hence omitted. Low levels of penicillin and nalidixic acid are also present in LJ medium to inhibit growth of gram positive and gram negative bacteria, in order to limit growth to Mycobacteria species only. Presence of malachite green in the medium inhibits most other bacteria. It is disinfected and solidified by a process of inspissation. Presence of glycerol enhances the growth of ''Mycobacterium tuberculosis''. If the slopes are made on test tubes they must be stored in cold and used within a month. For cultivation of ''M.bovis'', glycerol is omitted and sodium pyruvate is added. The medium appears green, opaque and opalescent. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Löwenstein–Jensen medium」の詳細全文を読む スポンサード リンク
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