An update to the original article has been published and is available using the links below.
Bart Veuger, Jack J. Middelburg, Henricus T.S. Boschker and Marco Houtekamer. Update of "Analysis of 15N incorporation into D-alanine: A new method for tracing nitrogen uptake by bacteria" (Veuger et al. 2005, L&O: Methods 3: 230-240).