A new rapid and simple method for large-scale purification of mycobacterial lipoarabinomannan

Lipoarabinomannan (LAM) is a major and structurally important outer cell wa il component of all mycobacteria. LAM is also generally regarded as an impo rtant immunomodulating substance affecting several immunologic networks and hence important in the pathogenesis of mycobacterial infections. We here d escribe a new method for large-scale purification of mycobacterial LAM. A c rude cell wall preparation was prepared from batch-grown Mycobacterium tube rculosis H37Rv. From this cell wall preparation LAM was purified by sequent ial extractions and chromatographic steps. From 20 g dry weight cell wall p reparation 313 mg of highly purified (> 98%) LAM was obtained in only 3 day s. The LAM content of the final purification step was quantified by ELISA u sing reference LAM as standard. The identity and purity of the LAM preparat ion was further confirmed by comparison with reference LAM preparation from M. tuberculosis strain Erdman in polyacrylamide gel electrophoresis and We stern blots, using reference anti-LAM monoclonals CS-35 and CS-40. (C) 1999 Federation of European Microbiological Societies. Published by Elsevier Sc ience B.V. All rights reserved.