What is the role of tannic acid in flagella staining?
Since flagella are too thin to be seen by compound light microscopy, staining methods employ the use of a mordant (often tannic acid) to make them thick enough to see using an oil immersion objective.
Are acidic stains used in flagellar staining techniques?
Flagella staining thickens the flagella by first applying mordant (generally tannic acid, but sometimes potassium alum), which coats the flagella; then the specimen is stained with pararosaniline (most commonly) or basic fuchsin (Figure 8).
What type of stain is Ryu stain?
Flagellar stains are painstakingly prepared to coat the surface of the flagella with dye or a metal such as silver. The number and arrangements of flagella are critical in identifying species of motile bacteria. Two techniques for staining flagella are in use: A wet-mount procedure (Ryu method)
Is tannin and tannic acid the same?
The main difference between tannin and tannic acid is that the term tannin is used to name a group of organic compounds, whereas tannic acid is a type of tannin. Tannins are organic compounds that fall under the category of polyphenols. These compounds contain several phenol groups in the same molecule.
Is crystal violet stain acidic or basic?
Product description: Crystal Violet is used as an acid-base indicator. When dissolved in water, the dye has a blue-violet colour with an absorbance maximum at 590nm and an extinction coefficient of 87,000 M-1 cm-1.
What is the difference between acidic and basic dyes?
Acid dyes based on a salt of a sulfuric, carboxylic or the phenolic organic acid. The salts are often sodium or ammonium salts. Basic dyes are cationic (+ve charged) and so will react with the material that is (-ve) negatively charged. Basic dyes are usually applied to Acrylic fibers.
Which stain is used for flagella of bacteria?
All flagella stains use mordants, like tannic acid and potassium alum, to coat and thus thicken the flagellum in order to be within the limits of size observable by light microscopy. The Leifson flagella stain method uses tannic acid (6, 7), while the Presque Isle method uses proprietary components.
What are the four types of flagella?
Based on their arrangement, bacteria are classified into four groups: monotrichous (having one flagellum), amphitrichous (single flagellum at both ends), lophotrichous (numerous flagella as a tuft), and peritrichous (flagella distributed all over the cell except at the poles).
Why are flagella stained with tannic acid?
Since flagella are too thin to be seen by compound light microscopy, staining methods employ the use of a mordant (often tannic acid) to make them thick enough … Bacterial flagella are appendages used for motility. Their presence is a useful tool for identification and differentiation of prokaryotes.
What is the flagella staining method?
It is a specialized staining method, which requires a combination of special reagents to stain the bacterial flagella. The flagella appear as narrow appendages, which cannot be visualized by employing common stains. Therefore, the flagella staining uses mordants to thicken the bacterial flagella that are too thin to be stained.
Why are flagella stained with mordant?
Since flagella are too thin to be seen by compound light microscopy, staining methods employ the use of a mordant (often tannic acid) to make them thick enough … Bacterial flagella are appendages used for motility.
How do you stain a bacterial culture with Ryu flagella?
If the motile cells are visible, the process is followed by staining the bacterial culture. Add a drop of Ryu flagella stain towards the one edge of the coverslip, which ultimately penetrates the bacterial suspension through capillary action.