paul ehrlich developed a useful staining method to identify acid-fast organisms.
paul ehrlich developed a useful staining method to identify acid-fast organisms.
who developed a useful staining method to identify acid-fast organisms?
paul ehrlich
ziehl–neelsen stain









































acid-fast stain, first introduced by dr. paul ehrlich, also known as the ziehl–neelsen staining, is a bacteriological stain used to identify acid-fast organisms, mainly mycobacteria. it is named for two german doctors who modified it: the bacteriologist franz ziehl (1859–1926) and the pathologist friedrich neelsen (1854–1898).
ziehl–neelsen stain
the "mycobacteria" have a cell envelope which is not typical of gram-positives or gram-negatives. the mycobacterial cell envelope does not consist of the outer membrane characteristic of gram-negatives, but has a significant peptidoglycan-arabinogalactan-mycolic acid wall structure which provides an external permeability barrier. therefore, there is thought to be a distinct 'pseudoperiplasm' compartment between the cytoplasmic membrane and this outer barrier. the nature of this compartment is not well understood. acid-fast bacteria, like "mycobacteria", are resistant to decolorization by acids during staining procedures. the high mycolic acid content of "mycobacteria", is responsible for the staining pattern of poor absorption followed by high retention. the most common staining technique used to identify acid-fast bacteria is the ziehl-neelsen stain or acid-fast stain, in which the acid fast bacilli are stained bright red and stand out clearly against a blue background.
cell envelope