Among fundamental developments in bacteriology the elaboration of solid culture substrates will always hold first place. With the introduction of a method for isolating micro6rganisms and growing them in pure culture, bacteriologists possessed the means for studying what Ferdinand Cohn (1872) called "Die kleinsten lebenden Wesen." Credit for the discovery of the solid medium technique is common...

We have read with interest the recent paper by Drancourt et al. in which they reviewed the use of blood agar medium for the primary isolation of Mycobacterium tuberculosis (2). They state that to their knowledge “no comparative study comparing the efficacy of blood-based agars and egg-based agars has been carried out, and even the ability of blood agar to support growth of M. tuberculosis was f...