Final answer:
To prepare a smear from a solid culture of a suspected Acid Fast species, one should mix the bacteria into a drop of water on a glass slide, allow it to air dry, then heat fix it before proceeding with the acid-fast staining technique.
Step-by-step explanation:
When preparing a smear from a solid culture of a suspected Acid Fast species, the correct sequence to prepare the sample for staining is to mix the bacteria into a drop of water on the glass slide, allow it to air dry, and then heat fix the slide by passing it briefly through the flame of a Bunsen burner. This process makes the bacteria adhere to the slide and is an important step prior to applying the acid-fast stain, such as the Ziehl-Neelsen technique. Once heat-fixed, a primary stain like carbol fuchsin is applied, and the slide is heated to allow stain penetration. Following a decolorization step and a counterstain application, acid-fast bacteria will appear pink, whereas non-acid-fast bacteria will be blue.
It is not recommended to apply the bacteria directly to the glass slide without water, nor to mix the bacteria with liquid broth before adding it to the slide. Heat should not be applied before the smear is made but rather after the smear has been air dried.