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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.
Wiki User
∙ 14y ago
Wiki User
∙ 15y agoA stain that differentiates the elements of a cell. examples are acid fast stain and gram stain
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What is the Difference between dyes and stains in biology?
a dye is used on inanimate objects & stain is used on animate objects .
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....
Can dyes or other methylene blue be used for direct staining?
Crystal violet, basic fuchsin, and safranin are all dyes which can be used in direct staining because they are cationic which means that they are positively charged. These dyes which are positively charged will react to the bacterial cell wall because the cell wall is negatively charged resulting in a basic stain.
Is safranin an acidic dye?
Sure, any basic stain can be used for simple, direct staining.
What is the stain most useful in clinicians to decide for bacterial infection?
Methylene blue a basic stain is generally used to identify the external morphology of bacteria.The other stain which is used as differential stain and which can also differentiate the baceteia on the basis of their cell wall is gram stain i.e. Crystal voilet and is counter stained with Saffranine
Why microbiologists use stains on cells?
Basic dyes have positively charged chromophore; thus, there target of binding affinity is the specimen or the microorganism which has a negatively charged cell wall. Through this, basic dyes can penetrate and making it an efficient stain for microorganisms.
What is an organic stain?
An organic stain is considered a biological stain using organic dye. Organic dyes used are often modified from the textile industry.
What is an auramine?
An auramine is any of a family of fluorescent dyes used to stain tissues for fluorescence microscopy.
What is the Difference between dyes and stains in biology?
a dye is used on inanimate objects & stain is used on animate objects .
When is Negative stain used?
it is used in diagnostic microscopy (to visualize the edges of protein complexes, macromolecules and cells in suspension).
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....
Can dyes or other methylene blue be used for direct staining?
Crystal violet, basic fuchsin, and safranin are all dyes which can be used in direct staining because they are cationic which means that they are positively charged. These dyes which are positively charged will react to the bacterial cell wall because the cell wall is negatively charged resulting in a basic stain.
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 part of speech is tincture?
The word tincture is a noun. (A pigment which dyes/an added colour) It can also be used as a verb. (to stain something with colour)
Is safranin an acidic dye?
Sure, any basic stain can be used for simple, direct staining.
What makes beet stain?
Early dyes were made of plant matter. One example is Indigo, now commonly used for blue jeans. Now it is a man-made chemical. But it was very popularly grown in India and Japan and was known in ancient civilizations around the world. Basically, when the microfibers of a material are dyed a different colour, something will stain. It can happen intentionally, like permanent marker, or unintentionally like... a food stain, or grass stain. Microfibers act as magnets to dyes, which is why, they are so hard to get rid of.
What is the stain most useful in clinicians to decide for bacterial infection?
Methylene blue a basic stain is generally used to identify the external morphology of bacteria.The other stain which is used as differential stain and which can also differentiate the baceteia on the basis of their cell wall is gram stain i.e. Crystal voilet and is counter stained with Saffranine
