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1 Gram stain
Developed by the Danish physician
"Hans Christian Gram"
Most commonly employed.
Important of all the diagnostic staining techniques.
By this method bacteria can be recognised as Gram-positive (blue-black) if they retain the primary dye complex of methyl violet and iodine in the face of attempted decolourization or as Gram-negative (red) if decolourisation occurs as shown by the cell accepting the counter stain.
Procedure:
Flood slide with crystal -10 seconds.
wash
Flood with Gram's iodine - 10 seconds.
wash
Carefully decolorize with 95% ethanol
wash
Flood with safranin (pink color) - 10 seconds.
wash
Air dry,
2 ZEIHL-NEELSEN'S METHOD (Acid-Fast Stain)
ACID FAST Os Contains waxlike lipoidal material affecting staining quality.
•Carbolfuchsin is primary stain.
•Acid fast organisms resist decolorization with acid alcohol.
•After decolorization, methyelene blue is added to organisms to counterstain any material that is not acid fast.
•It is used for examination of Mycobacterium.
•The principle of staining is depend on the resistance of this type of bacteria to decolarization by acid alcohol, because the cell wall contain waxy material (mycolic acid) which prevent the removal of carbol fuchsin from the cell.
Staining Procedure
Flood the slide with strong carbol fuchsin and heat until steam rises (but do not boil).
After 3-4 min apply more heat until rises again; do not let the stain dry on the slide.
About 5-7 min after the first application of heat washes the slide thoroughly under running water.
Decolourize in acid-alcohol until all traces of red have disappeared from the film. Decolourization should not be attempted in one stage; there should be intermittent washings in water and re-application of acid-alcohol.
Wash well with water and counter stain with Methylene blue for 1 min.
Wash and stand end to drain.
Acid-fast organisms are red, other organisms are blue.
What else can I help you with?
What is the stain used to staines the cell membrane?
The stain commonly used to stain the cell membrane is called lipophilic fluorescent dyes, such as DiI or DiO, which incorporate into the cell membrane due to their hydrophobic nature. These dyes are often used in microscopy to visualize cell membranes within cells or tissues.
Identify a stain that would be appropriate for improving definition of the blood cells?
Wright's stain is a commonly used stain in hematology that improves the definition of blood cells, particularly white blood cells. It consists of a combination of acidic and basic dyes, allowing for better visualization and differentiation of various blood cell types.
Why an acidic stain is used in negative staining?
Acidic dyes are negatively-charged dyes. Since bacteria are also negatively-charged, they will repel the acidic dyes. So, instead of staining the bacterium itself, it will be the background that will be colorized....
What is the principle of leishman stain?
It is basically use to stain leukocytes,maleria prasite and trypanosomas. leisman stain contain 1st methylene blue dye, a basic dye, which gives color to an acidic component.2nd eosin dye,an acidic dye ,which gives color to a basic component. These dye differentiat the different component of blood.
Is counterstain a negative stain?
No, counterstain is not a negative stain. A counterstain is a secondary stain used in microscopy to color structures that were not stained by the primary stain, usually to provide contrast. Negative staining involves staining the background instead of the cells or structures of interest.
What is the difference in basic dyes and acidic ones?
Basic dyes are positively charged and are commonly used to stain acidic materials, such as nucleic acids, whereas acidic dyes are negatively charged and are used to stain basic materials, like proteins. The choice of dye depends on the target material's charge characteristics to achieve optimal staining results.
What is the difference between Wright stain and Giemsa stain?
The Wright stain is a combination of eosin and methylene blue dyes, while Giemsa stain is a mixture of eosin, methylene blue, and azure dyes. Giemsa stain is commonly used for staining blood smears to visualize parasites and bacteria, while Wright stain is used more for general cell morphology in blood and bone marrow specimens.
Why microbiologists use stains on cells?
Basic dyes are used to stain bacteria because most bacteria is negatively charged, so positively charged basic dyes stick to bacteria walls. Basic dyes include crystal violet, methylene blue, safranin, malachite green.
What is the stain used to staines the cell membrane?
The stain commonly used to stain the cell membrane is called lipophilic fluorescent dyes, such as DiI or DiO, which incorporate into the cell membrane due to their hydrophobic nature. These dyes are often used in microscopy to visualize cell membranes within cells or tissues.
Identify a stain that would be appropriate for improving definition of the blood cells?
Wright's stain is a commonly used stain in hematology that improves the definition of blood cells, particularly white blood cells. It consists of a combination of acidic and basic dyes, allowing for better visualization and differentiation of various blood cell types.
Why do all cells stain purple in the flagella stain but not in the gram stain?
In the flagella stain, all cells appear purple due to the basic dyes used to stain the flagella. This uniform coloration helps visualize the flagella structure under the microscope. In contrast, the Gram stain uses a series of dyes to differentiate between Gram-positive (purple) and Gram-negative (pink) cells based on their cell wall composition.
What is an auramine?
An auramine is any of a family of fluorescent dyes used to stain tissues for fluorescence microscopy.
Why an acidic stain is used in negative staining?
Acidic dyes are negatively-charged dyes. Since bacteria are also negatively-charged, they will repel the acidic dyes. So, instead of staining the bacterium itself, it will be the background that will be colorized....
What dye is used in a vital stain?
A vital stain is a dye that is utilized to selectively stain living cells without affecting their viability or function. Common dyes used for vital staining include trypan blue, propidium iodide, and calcein-AM. These dyes can help distinguish between live and dead cells in various biological assays.
What is the difference between acidic dye and basic dye?
basic dyes are more effective for bacterial staining than acidic dyes because basic dyes have a positive charged chromogen. Bacterial nucleic acids and certain cell wall components carry a negative charge that strongly binds to the cationic chromogen.
Why doesn't the whole cell stain with the cell-wall stain?
The whole cell doesn't stain during a cell wall stain because the dyes that are used are only attracted to the negative cell wall and only sticks it. The inside of the cell shows clear.
What is the principle of leishman stain?
It is basically use to stain leukocytes,maleria prasite and trypanosomas. leisman stain contain 1st methylene blue dye, a basic dye, which gives color to an acidic component.2nd eosin dye,an acidic dye ,which gives color to a basic component. These dye differentiat the different component of blood.
