Acid Fast Stain

∞ generated and posted on 2016.09.07 ∞

Means of colorizing during microscopy of bacteria possessing waxy cell envelopes such as those found in genus Mycobacterium.

The Acid-Fast Stain is a means of differential staining so-called acid-fast bacteria – which includes most notably members of genus Mycobacterium – that is, as part of the means of distinguishing these organisms from, non-acid-fast bacteria as well as simply viewing them using a bright-field light microscope.

Bacteria that stain in this manner are described as acid fast. See also Ziehl-Neelsen stain.

The acid-fast stain is an example of a differential stain, as too is the Gram stain. Contrast with simple stain.

A little slow (watch at 1.25× speed if you can), but does a good job of showing how the stain is performed as well as what the results look like:

There in fact are quite a number of additional YouTube videos on Acid-fast staining.