Staining - Page 4 of 4 - Biology Notes Online

Toluidine Blue Staining – Principle, Procedure, Results and Uses

Sourav Pan (M.Sc. in Microbiology) • Updated October 28, 2026 • 18 min read

Schematic comparing separate toluidine blue dye cations producing blue orthochromatic staining with aggregated dye on negatively charged glycosaminoglycans producing purple-red metachromasia.

Toluidine blue staining explained with its principle, preparation, procedure, results, mast cell staining, histological uses, and limitations.

Iron-Hematoxylin Staining – Principle, Procedure, Uses

Sourav Pan (M.Sc. in Microbiology) • Updated October 28, 2026 • 12 min read

Iron-hematoxylin-stained amoebic trophozoite with one nucleus beside a mature four-nucleated cyst, showing karyosomes, peripheral chromatin and grey-blue cytoplasm.

Hematoxylin is extracted from a leguminous plant, known as Haematoxylon campechianum, thus it is a natural dye. It forms hematein by oxidation (Ripening).

Acridine Orange Staining – Principle, Procedure, Uses

Sourav Pan (M.Sc. in Microbiology) • Updated October 28, 2026 • 14 min read

Fluorescence microscopy schematic showing bright orange bacterial cells, green-yellow host cells, and fluorescent debris in an acridine orange-stained clinical smear.

Acridine Orange contains metachromatic properties, that’s why it is employed in fluorescence microscopy and flow cytometry study of cellular physiology and cell cycle state, including the fluorescent microscopic examination of microorganisms.

Kinyoun Stain Method – Principle, Procedure and Results

Sourav Pan (M.Sc. in Microbiology) • Updated October 28, 2026 • 15 min read

Comparison of Kinyoun-stained microscopic fields showing slender red acid-fast bacilli in a positive preparation and blue counterstained non-acid-fast bacteria in a negative preparation.

Kinyoun stain method explained with its principle, reagents, procedure, result interpretation, modifications, applications, and Ziehl-Neelsen comparison.

Ziehl-Neelsen Staining (ZN Staining) – Principle, Procedure and Results

Sourav Pan (M.Sc. in Microbiology) • Updated October 27, 2026 • 19 min read

Diagram showing acid-fast bacilli retaining red carbol fuchsin after acid treatment, while non-acid-fast cells become blue after counterstaining.

Ziehl-Neelsen Staining (ZN Staining): principle, reagents, procedure, positive and negative results, AFB smear grading, modified methods, and limitations.

Lactophenol Cotton Blue (LPCB) Staining – Principle and Procedure

Sourav Pan (M.Sc. in Microbiology) • Updated October 27, 2026 • 13 min read

Lactophenol Cotton Blue Staining of aspergillus

Lactophenol Cotton Blue (LPCB) Staining covers the principle, composition, solution preparation, fungal wet-mount procedure, microscopic results, and limitations.

Sudan Black B Staining – Principle, Procedure and Results

Sourav Pan (M.Sc. in Microbiology) • Updated October 27, 2026 • 16 min read

Comparative microscopy illustration showing blue-black lipid droplets in frozen tissue, dark intracellular bacterial inclusions, and cytoplasmic granules in a Sudan Black B-positive neutrophil.

Sudan Black B staining guide covering its principle, reagents, frozen-section and bacterial smear procedures, positive results, applications and limitations.

Parasporal Crystal Staining – Principle, Procedure and Results

Sourav Pan (M.Sc. in Microbiology) • Updated October 26, 2026 • 10 min read

Four illustrated microscope fields comparing visible blue parasporal crystals, no detectable crystals, irregular stain deposits and a crowded smear.

Parasporal crystal staining explained with its principle, Coomassie Brilliant Blue procedure, required materials, microscopic results, uses and limitations.

Flagella Staining – Principle, Reagents, Procedure and Results

Sourav Pan (M.Sc. in Microbiology) • Updated October 26, 2026 • 15 min read

Comparison of a thin bacterial flagellum before staining, mordant-assisted dye deposition around the filament, and a thicker stained flagellum visible under light microscopy.

Flagella staining in microbiology – principle, reagents, Ryu and Leifson methods, step-by-step procedures, result interpretation, and limitations.

Bacterial Smear Preparation – Principle, Materials and Procedure

Sourav Pan (M.Sc. in Microbiology) • Updated October 25, 2026 • 16 min read

Workflow showing bacterial smear preparation from broth culture and agar colonies, followed by spreading and complete air-drying on glass slides.

Bacterial smear preparation explained with its principle, materials, procedure from broth and agar cultures, fixation methods, and precautions.