ALBERTS STAIN REPORT

Special stains have been developed over time for identifying bacteria species, differentiating them morphologically, and even characterizing there very special features. The most common stain being Gram Staining, Acid-fast staining, endospore staining. Each of these stains aims at identifying and characterizing bacteria based on their morphologies.

Albert Staining- Principle, Reagents, Procedure, Results, Interpretation

February 1, 2022 by Faith Mokobi

Edited By: Sagar Aryal

Special stains have been developed over time for identifying bacteria species, differentiating them morphologically, and even characterizing there very special features. The most common stain being Gram Staining, Acid-fast staining, endospore staining. Each of these stains aims at identifying and characterizing bacteria based on their morphologies.

Albert stain is no different. Its application aim at identifying bacteria that contain special structures known as metachromatic granules. Other staining techniques that are used to detect the presence of granules in the cytoplasmic membrane of bacteria are Nessers’s stain and Pugh’s stain.

Albert stain distinctly identifies metachromatic granules that are found in Corynebacterium diphtheriae. 

Corynebacteria are gram-positive, non-spore forming, non-motile bacilli that contain metachromatic (Volutin) granules which are intracellular inclusion bodies, found in the cytoplasmic membrane of some bacterial cells for storage of complexed inorganic polyphosphate (poly-P) and enzymes. When these granules are subjected to stain with methylene blue dye, they appear reddish-purple color and not the blue dye.

The most common Corynebacterium is Corynebacterium diphtheriae, that caused diphtheria, a nasopharyngeal infection (affecting the nasal, throat) that can also affect the skin, after bacterial colonization and infection.

Basically, this bacteria is initially cultured in selective media either a Loeffler agar or Mueller-Miller tellurite agar, or Tinsdale tellurite agar, and its colonize isolated to prepare liquid culture that is then used for staining. Albert stain only acts as a confirmatory stain for the bacteria. Being a differential stain, it can only stain volutin granules, hence bacteria without these granules can not be stained nor identified with this technique.